tame parrot
In-game mutes by ToxMod are clear: You'll see a pop-up warning when you start the game, and again when you try to toggle your mic off/on while on the tables.
If this is the case, start here: #🦻🏼toxmod-questions message
If others on the table can't hear you & you don't get those pop-up warnings, it's time to review your Meta settings.
Other VR communities have posts about this, too - the headset itself glitches out on occasion.
Check your mic information in Settings > Apps > Microphone settings. If your mic is already turned on, toggle it off and on again as shown in the video below, then restart your game and you should be good to go!
HERE'S A TEST TO TRY:
If you wonder whether it's your device, or the app - drop into the Meta home space and record a video with your mic turned on. Talk for a few moments, stop the video, and review it to find out if you can hear yourself or not. You may need to reach out to Meta Support for assistance with your Quest directly.
Reach out to @tame parrot or @west slate if you continue to have troubles.