Mic not working on PC, can't assign push to talk button on controller either.

I'm using a mic plugged into a 3.5mm jack on my desktop, AL doesn't seem to recognize it. When set to open mic, the little bar above it doesn't register any sound (should it?) coming from the mic.

Furthermore, I play with a controller on PC, and if I set PTT as my mic option there does not seem to be a controller button mapped for it, and worse, there's no way to map it. What's up with that?