If you need to activate licenses for different servers you need to buy them separately. For example, if you need 5 licenses to server A and more 10 to server B, add 5 licenses to the cart and then add 10 more again, you'll receive two activation codes, one for each server.

apt-get install freeswitch-mod-com-amd

<load module="mod_com_amd"/>

freeswitch-license-validator

 
		freeswitch product licencing tool
		You will require one or more sales codes to activate licences

		Enter a sales code, or a blank line to end: 0abd19753bf28fbb88a5d74
		Enter a sales code, or a blank line to end:

		Sales codes to be activated:
		0abd19753bf28fbb88a5d74
		OK (Y/N)? y

		Success. The file licences.zip contains valid licences.
		Unzip this to /etc/freeswitch/

unzip licences.zip

		Archive:  licences.zip
		inflating: 0abd19753bf28fbb88a5d74.conf

cp 0abd19753bf28fbb88a5d74.conf /etc/freeswitch

systemctl stop freeswitch 

freeswitch-license-server
 
		Scanning /etc/freeswitch/0abd19753bf28fbb88a5d7.conf for licences
		Purchase code 0abd19753bf28fbb88a5d74
		10 channels of AMD

systemctl start freeswitch

fs_cli -x amd_info
 
		Success checking AMD/0
		AMD license available => 10
		AMD license allocated => 0

    <extension name="amd_test" continue="false">
      <condition field="destination_number" expression="^(amd|263)$"/>
      <condition field="${amd_available()}" expression="true">
      <!-- alternate way of checking channel availability -->
      <!--<condition field="${regex ${amd_info}|available => 0}" expression="false">-->
        <!-- <action application="set" data="media_bug_answer_req=true"/> -->
        <action application="set" data="amd_execute_on_machine=transfer machine_found XML default"/>
        <action application="set" data="amd_execute_on_person=transfer person_found XML default"/>
        <action application="set" data="amd_execute_on_unsure=transfer amd_unsure XML default"/>
        <!-- <action application="set" data="api_on_answer=uuid_displace ${uuid} start ${sounds_dir}/Answering_Machine.wav 0 mr"/> -->
        <action application="answer"/>
        <action application="voice_start"/>
        <action application="playback" data="silence_stream://100,1000"/>
        <action application="playback" data="tone_stream://(2000,4000,440,480)"/>

        <!-- <action application="waitforresult" data="ivr/ivr-one_moment_please.wav"/> -->
        <!-- <action application="waitforresult"/> -->
        <!-- <action application="sleep" data="200"/> -->
        <!-- <action application="playback" data="tone_stream://%(200,100,500,400,300,50,25);loops=2"/> -->
        <action application="sleep" data="20000"/>
        <!-- <action application="log" data="CRIT AMD Result is => ${amd_status} => ${amd_result}"/> -->
        <action application="hangup"/>
        <anti-action application="playback" data="${sounds_dir}/All_Circuits_Busy.mp3"/>
        <anti-action application="hangup"/>
      </condition>
    </extension>
    <extension name="Found Machine">
      <condition field="destination_number" expression="^(machine_found)$">
        <action application="playback" data="ivr/ivr-welcome_to_freeswitch.wav"/>
        <action application="log" data="CRIT AMD result is => ${amd_status} and AMD Status is => ${amd_result}"/>
        <action application="voice_stop"/>
        <action application="hangup"/>
      </condition>
    </extension>
    <extension name="Found Person">
      <condition field="destination_number" expression="^(person_found)$">
        <action application="playback" data="misc/if_you_are_this_person.wav"/>
        <action application="log" data="CRIT AMD result is => ${amd_status} and AMD Status is => ${amd_result}"/>
        <action application="voice_stop"/>
        <action application="hangup"/>
      </condition>
    </extension>
    <extension name="AMD Unsure">
      <condition field="destination_number" expression="^(amd_unsure)$">
        <action application="playback" data="misc/error.wav"/>
        <action application="log" data="CRIT AMD result is => ${amd_status} and AMD Status is => ${amd_result}"/>
        <action application="voice_stop"/>
        <action application="hangup"/>
      </condition>
    </extension>

This is the preferred method for checking channel availability

<condition field="${amd_available()}" expression="true">

or you can see if license are available by checking a regex against zero using the amd_info api

<condition field="${regex ${amd_info}|available => 0}" expression="false">

if regex is false, then proceed with amd usage, else if true, do anti actions to notify customer with a custom sound file

<anti-action application="playback" data="${sounds_dir}/All_Circuits_Busy.mp3"/>
<anti-action application="hangup"/>

Notes on the parenthesis "()":

example for "false" when channels are available for use:

CORRECT USAGE DIALPLAN: without the parens, yields PASS:

  <condition field="${regex ${amd_info}|available => 0}" expression="false">
Log:
  Dialplan: sofia/internal/1003@192.168.150.3:65062 Regex (PASS) [amd_test] ${expand regex ${amd_info}|available => 0}(false) =~ /false/ break=on-false

INCORRECT USAGE: Dialplan with the parens, yields -ERR:
  <condition field="${regex ${amd_info()}|available => 0}" expression="false">
Log:
  Dialplan: sofia/internal/1003@192.168.150.3:65062 Regex (FAIL) [amd_test] ${regex ${amd_info()}|available => 0}(-ERR) =~ /false/ break=on-false

example for "true" when all channels are currently in use

CORRECT USAGE ESL: with the parens
freeswitcha> expand regex ${amd_info()}|available => 0
true

INCORRECT USAGE ESL: without the parens
freeswitcha> expand regex ${amd_info}|available => 0
false

cd /tmp 
wget http://files.freeswitch.org/amd/fs-latest-installer 
chmod +x fs-latest-installer 
./fs-latest-installer

./fs-latest-installer <bin_path> <mods_path> <config_path>

Thank You!
Running Installer
Stopping license server
Installing new license server
Installing new FreeSWITCH module
Installing activation utility
Creating license directory
Running ldconfig...
Cleaning up... 

Now you can activate your product license(s) by running /usr/local/freeswitch/bin/validator

Thank you

Done.

<configuration name="amd.conf" description="AMD Configuration">
  <!-- AMD -->
  <settings>
	<!-- silent_threshold: The level of volume to consider talking or not talking, same scale as used in mod_conference -->
    <param name="silent_threshold" value="256"/>
	<!-- silent_initial: Time in ms for there to be silence after answer in order to result in "silent-initial" with status of person -->
    <param name="silent_initial" value="4500"/>
	<!-- silent_after_intro: Time in ms after an initial non silent greeting in order to result in silent-after-intro with status of person -->
    <param name="silent_after_intro" value="1000"/>
	<!-- silent_max_session: Time in ms of total silence before we allow detection to complete -->
    <param name="silent_max_session" value="200"/>
	<!-- noise_max_intro: Time in ms length of initial intro over which in order to result in max-intro with status of person -->
    <param name="noise_max_intro" value="1250"/>
	<!-- noise_min_length: Time in ms minimum to be considered a word  -->
    <param name="noise_min_length" value="120"/>
	<!-- noise_inter_silence: Time in ms of silence to be considered a word break -->
    <param name="noise_inter_silence" value="30"/>
	<!-- noise_max_count: If we have more than this many noise hits (words) result will be "max-count" with status of machine -->
    <param name="noise_max_count" value="6"/>
	<!-- total_analysis_time: total time in ms that we will try to analyze a call -->
    <param name="total_analysis_time" value="5000"/>
	<!-- debug: set to 1 to get more debug information -->
    <param name="debug" value="1"/>
  </settings>
</configuration>

        <action application="voice_start" data="silent_threshold=96,
                                                silent_initial=3500,
                                                silent_after_intro=1500,
                                                silent_max_session=200,
                                                noise_max_intro=2250,
                                                noise_min_length=175,
                                                noise_inter_silence=50,
                                                noise_max_count=10,
                                                total_analysis_time=5000,
                                                debug=1"/> 

<extension name="amd_example" continue="false">
  <condition field="destination_number" expression="^5551212$">
    <action application="set" data="media_bug_answer_req=true"/>
    <action application="set" data="amd_execute_on_machine=transfer machine_detected XML default"/>
    <action application="voice_start"/>
    <action application="playback" data="/usr/local/freeswitch/sounds/en/us/callie/ivr/8000/ivr-welcome_to_freeswitch.wav"/>
    <action application="playback" data="/usr/local/freeswitch/sounds/en/us/callie/ivr/8000/ivr-welcome_to_freeswitch.wav"/>
    <action application="playback" data="/usr/local/freeswitch/sounds/en/us/callie/ivr/8000/ivr-welcome_to_freeswitch.wav"/>
    <action application="playback" data="/usr/local/freeswitch/sounds/en/us/callie/ivr/8000/ivr-welcome_to_freeswitch.wav"/>
    <action application="info"/>
    <action application="hangup"/>
  </condition>
</extension>

<extension name="Found machine">
  <condition field="destination_number" expression="^(machine_detected)$">
    <action application="wait_for_silence" data="300 30 5 25000"/>
    <action application="sleep" data="8000"/>
    <action application="playback" data="/usr/local/freeswitch/sounds/en/us/callie/ivr/8000/ivr-welcome_to_freeswitch.wav"/>
    <action application="info"/>
    <action application="hangup"/>
  </condition>
</extension>

bgapi originate {ignore_early_media=true}sofia/profile/number 5551212

local dst_number = argv[1]
-- Connecting to the freeswitch API.
api = freeswitch.API()
use_amd = api:executeString("amd_available")

subscriber_session = freeswitch.Session("{ignore_early_media=true}sofia/gateway/mygw/" .. dst_number)

while (subscriber_session:ready() and not subscriber_session:answered()) do
  -- Waiting for answer.
  freeswitch.msleep(500)
end

if subscriber_session:ready() and subscriber_session:answered() then
  freeswitch.consoleLog("INFO", string.format("Number answered call %s.", dst_number))
  freeswitch.consoleLog("INFO", string.format("AMD Enable on %s.", dst_number))
  if use_amd == "true" then
    subscriber_session:execute("voice_start")
    -- Giving some time to AMD to work on the call.
    subscriber_session:sleep(3000)
    subscriber_session:execute("voice_stop")
    amd_detect = subscriber_session:getVariable("amd_status")
    if amd_detect == "machine" then
      freeswitch.consoleLog("INFO", "amd_status: machine")
      subscriber_session:execute("wait_for_silence", "300 30 5 25000")
	  subscriber_session:execute("playback", "/usr/local/freeswitch/sounds/en/us/callie/ivr/8000/ivr-welcome_to_freeswitch.wav")
      subscriber_session:hangup()
      return
    end
	-- Do your actions if human answered. Ex. Transfer to operator/user 100.
    subscriber_session:execute("bridge", "user/100")
  end
else
  freeswitch.consoleLog("INFO", string.format("Cannot call %s", dst_number))
  return
end

luarun dialer.lua 55552222

    <extension name="amd_test" continue="false">
      <condition field="destination_number" expression="^(amd_test|263)$">
        <action application="set" data="media_bug_answer_req=true"/>
        <action application="set" data="amd_execute_on_machine=transfer machine_found XML default"/>
        <action application="set" data="amd_execute_on_person=transfer person_found XML default"/>
        <action application="set" data="amd_execute_on_unsure=transfer amd_unsure XML default"/>
        <action application="voice_start"/>

        <action application="set" data="api_on_answer=uuid_displace ${uuid} start ${sounds_dir}/Answering_Machine.wav 0 mr"/>
        <action application="answer"/>

        <action application="waitforresult" data="ivr/ivr-one_moment_please.wav"/>

        <action application="sleep" data="200"/>
        <action application="playback" data="tone_stream://%(200,100,500,400,300,50,25);loops=2"/>
        <action application="sleep" data="200"/>
        <action application="log" data="CRIT AMD Result is => ${amd_status} => ${amd_result}"/>
        <action application="hangup"/>
      </condition>
    </extension>

    <extension name="Found Machine">
      <condition field="destination_number" expression="^(machine_found)$">
        <action application="playback" data="ivr/ivr-welcome_to_freeswitch.wav"/>
        <action application="log" data="CRIT AMD result Machine Found is => ${amd_status} => ${amd_result}"/>
        <action application="voice_stop"/>
        <action application="hangup"/>
      </condition>
    </extension>

    <extension name="Found Person">
      <condition field="destination_number" expression="^(person_found)$">
        <action application="playback" data="misc/if_you_are_this_person.wav"/>
        <action application="log" data="CRIT AMD result Machine Found is => ${amd_status} => ${amd_result}"/>
        <action application="voice_stop"/>
        <action application="hangup"/>
      </condition>
    </extension>
	
    <extension name="AMD Unsure">
      <condition field="destination_number" expression="^(amd_unsure)$">
        <action application="playback" data="misc/error.wav"/>
        <action application="log" data="CRIT AMD result Machine Found is => ${amd_status} => ${amd_result}"/>
        <action application="voice_stop"/>
        <action application="hangup"/>
      </condition>
    </extension>

uuid_displace have options [m]ux and [r]ead, so you can hear the ensuing found extension audio, and also induce the answering machine file onto the read channel so amd can operate on it.

mod_amd - Answering Machine Detection for FreeSWITCH
mod_amd supplies three different dialplan apps and several channel variables.
It also fires events during the detection process. They are listed here for reference.
Apps:
voice_start - starts the answering machine detection on a channel
voice_stop - stops the answering machine detection on a channel
waitforresult [<file to play while while waiting>] - waits for AMD to return a result, and optionally playback a file
Channel variables, results:
amd_status - Contains whatever was detected:
'person', 'machine', 'unsure'
Basically, anything other than 'machine' should be assumed to be a human
amd_result - Contains more information about what was detected:
'too-long' - detection process took longer than total_analysis_time (amd.conf.xml)
'max-count' - max noisy frames detected, probably a machine speaking
'max-intro' - max noisy frames detected during intro, probably a machine speaking
'silent-initial' - nothing heard on line, assume human
'silent-after-intro' - short burst of noisy frames followed by silence - probably human
Channel variables, control:
execute_on_machine_app - application to execute if machine detected
execute_on_machine_arg - argument to application to execute if machine detected
Events:
CUSTOM::AMD::EVENT - Action: Start Talking
CUSTOM::AMD::EVENT - Action: Stop Talking
SWITCH_MEDIA_BUG_ADD - Fired at start of detection process
SWITCH_MEDIA_BUG_REMOVE - Fired at stop of detection process
Look for variable_amd_status header
USAGE
mod_amd can be used three ways:
via event socket, where an event-based script watches for AMD events and acts accordingly
via the supplied JavaScript file
via the dialplan by setting "execute_on_machine_app" and "execute_on_machine_arg"
See default.xml for simple examples