Pressing "G" or "T" to enable voice chat shows the voice chat indicator (and can me transmitting is seen by other players), but other players cannot hear me.
There are no Microphone device options in-game. To alleviate, I attempted setting my microphone in Steam Friends/Voice settings but this did not fix the issue.
Press "G" or "T" and attempt to use Voice Chat.
After some further tinkering it seems Reforger was using my Meta Quest 2 as its input device despite the Quest being disconnected and turned off. I reset the Windows default Input Device to my microphone and this seemed to fix the issue.
Would still appreciate having an Input Device selection option in the in-game settings for users who have multiple input devices.