Google gave me the following translation for the post above;
I have checked that the plugin that allows to answer calls by sending a SIP notify is only prepared for chan_sip. If Pjsip is used, the action is Pjsipnotify. Is it possible to adapt it? The parameters are the same (in the case of Yealink), only the Action changes.
I wanted to say that I noticed the same. PJSIP extensions can't use the answer button and I'd like to see this fixed.
Also, I'm personally having issues with yealink T46 phones with the latest firmware (and older firmware). Even using chan_sip the answer button hasn't worked for me. However T22P (now discontinued) work fine when using chan_sip. I must be missing something because I'd expect the T46 to handle this.