Mic for webcam

Hi all, I have a presonus firestudio project.

My plan is teach guitar online through a webcam, I’ve tried a few different platforms and all pick up my presonus, however, I’m only able to use one mic?? I mic up my voice and amp. Only Input 1 seems to work? I can see input 2 is picking up my feed, just no one hears it on the other end.

Any help please!!