Combining manager API, with fast AGI

Hi there,
I am using the manager API to originate call to another party, “sip soft phone” ,

then send the originate action
where 300 is the extension of the called phone,
as result of running the program, the phone receive an incoming call, but when answer I hear no thing, as the call hung up immediately!!!

what I am missing :unamused: ?

Thanks in advance