Managing sound and video settings during Teams meetings and calls
Are you using this webcam?
https://www.amazon.com/Microphone-NexiGo-Computer-110-degree-Conferencing/dp/B088TSR6YJ?th=1
Nevertheless, this webcam and the built-in microphone are not detected by Windows on your desktop PC.
Perhaps you can try to disconnect this webcam and connect to another USB port. Avoid using any unpowered USB hub. Connect this webcam directly to an USB 2.0 port on your PC. Make sure that the Privacy Protection Cover is open.
Check if the webcam is working in Windows Camera app.