Voice chat not working (Please help)

My ingame voice chat isn’t working. Even with “Auto Transmit Voice” on, there is no sound coming from my microphone. If I change the key binding to something else and then reapply it to V, there is still no sound coming from my microphone. I think it is only not working on Rust, because my headset works for other things like Discord. I think my Rust game is a little broken too, because when I change 1 little setting ingame, it crashes. Can anyone please help me?

If you attempt to talk does the greenbar jump up or does it stay as it is.

If not go to the Sound settings in windows and set youre microphone to “Primary Communication Device”

thats how i fixed it.

I have Windows 8.1. Where are the sound settings that you speak of that I can set my microphone to the “Primary Communication Device”?