Microphone not working as input in garage band

I'm trying to set up garageband on my new macmini. When I launch it, it seems to recognize my external microphone. The external microphone works for other applications, such as zoom, and registers as a sound input. When the track opens up in garage band, it says "no input" and I can't access the microphone. I've tried security settings in preferences, and garage band is not listed as allowed to access the microphone, but it does not appear to be asking permission to access the microphone. Any suggestions?

Garageband newbie