Mac Studio Internal microphone not working

The image you posted says it all "No Audio Input Devices Found" and as already mentioned there is no internal microphone on the Mac Studio. You need to add a your own microphone as an accessory. For example I use a display/monitor with my Mac Studio that has a built-in microphone.

I also sometimes use a simple USB microphone or an audio interface connected to my Mac Studio to use a variety of microphones depending on what project I am working on.

Built in speaker but no mic