Not able to make a call to conf bridge/Toll free number

Hi Experts,

I am new to Asterisk, Adhearsion and Ruby code and this is my 1st development App.
I am using Asterisk 1.8 and Adhearsion 2.3 on EC2 instance and currently struggling to make a outbound call to a toll free bridge number.

I can make a call to any toll free number, but not able to pass the moderator and participants passcode.

I got some reference code from web and working on same:
Fosedom2013 (github.com/polysics/fosdem2013)

My requirement_handler.rb file (from “/ahn/lib”) has below code which is failing at line “execute senddtmf”

Here is my file contents: requirement_handler.rb:

Adhearsion::OutboundCall.originate “SIP/TollFreeNumber@TRUNKNAME” do
sleep 4
# enter moderator pin number
execute ‘senddtmf’, ‘ModNumber#’
# call moderator
dial ############

Not sure why this execute senddtmf is not working. Please help me to resolve this issue.

Waiting for all your valuable help and suggestions.

Regards,
Sangram