Apple's documentation says that once an app joins a Push to Talk channel, pressing "play" on a headset should start recording. On my iPhone it doesn't. Both the M015(our earbud) and AirPods send the press to Apple Music instead. The phone's own log says "No context for this command", then opens Music. So we ask Apple: What exactly has to be true for the earbud press to reach Push to Talk instead of Music? Does it work at all when nothing is playing? Can one press start and the next press stop, or is it press-and-hold only? Is a Bluetooth data signal from the earbud the only other way?

"Why doesn't the earbud button start Push to Talk?"

Apple's documentation says that once an app joins a Push to Talk channel, pressing "play" on a headset should start recording. On my iPhone it doesn't. Both the M015(our earbud) and AirPods send the press to Apple Music instead. The phone's own log says "No context for this command", then opens Music. So we ask Apple:

What exactly has to be true for the earbud press to reach Push to Talk instead of Music?
Does it work at all when nothing is playing?
Can one press start and the next press stop, or is it press-and-hold only?
Is a Bluetooth data signal from the earbud the only other way?