MacOS Microphone Permission
MacOS requires any application that wants to use the microphone to show a permission dialog.
Since Minecraft itself doesn't need the microphone, we are not able to request access for it. However, some launchers add the ability to ask for microphone permission.
In order to use the voice chat on MacOS, you need to use Prism Launcher.
NOTE
If you have issues installing or setting up the launcher, visit the Prism Launcher Discord server for help.
Please don't ask them for help with the voice chat mod itself!