Is push to talk for voice chat not a thing?

Are we forced to have open mic or muted mic and not able to use push to talk? I cannot find anything about push to talk anywhere.

Currently there is no official way to use push-to-talk from my knowledge.

No, there is no way to have push to talk unless you use an external application that messes with your microphone to disable and enable it when you press a keybind.
OFFTOPIC:
Honestly the voicechat is a great a feature and cool to have but theres lack of usage for us developers with it, if we could have systems to detect when someone is talking and ways to determine how high the volume is or if the user is talking or not, we could create lots of unique games with it. Roblox voicechat is good, just lacking.