How to pass a parameter to DYNAMIC_FEATURES?

Question

Asterisk

Hello, dear site visitors. I'm trying to set up sending faxes on asterisk by dialing a certain combination using this article habrahabr.ru/post/245271/, but with reference to extension. There is the following construction:
1. features.conf
fax_send => *3,callee,Macro(fax)
2. extensions.conf
[from-internal]
exten => _XX.,n,Set(DYNAMIC_FEATURES=fax-send)
[macro- fax]
<....>
The fact is that the macro-fax context does not know anything about the internal number of the subscriber who transferred the call to it. How to pass a parameter from the from-internal context when passing to fax_send? For example, the extension number (I want macro-fax to take a file called the extension that ran this macro). If the macro is called without features, then there is no problem. Thank you in advance.
Sincerely, dexxxqqq

Answer 1

I asked myself, I answer. To inherit a variable, you need to put an underscore character.
extensions.conf
[from-internal]
exten => _XX.,1,Set(DYNAMIC_FEATURES=fax-send)
exten => _XX.,n, Set(_FAXFILENAME=${CALLERID(NUM)})
[macro-fax]
< ....>
<....>