How to force G729 annexb=no appears in SDP on a pjsip trunk

I’m doing an IOT test with a carrier and they need G729 annexb=no appears in the SDP in the INVITE.
In a chan_sip trunks it is always there but since I have use pjsip to support rfc3262 there is no fmtp:18 annexb=no

Any thought?

You’re correct. It seems that was forgotten. Could you open an issue about it on the issue tracker [1] ?

[1] -