Choose a camera or microphone for FaceTime calls on Mac
If your Mac is connected to multiple cameras, microphones or output devices, you can choose which one to use for your FaceTime audio and video calls.
In the FaceTime app on your Mac, make a selection from the Video menu.
Choose Use System Setting for your microphone or output device.
Choose a specific camera, microphone, or output device to use.
If there aren’t any devices listed in the Video menu, FaceTime uses the built-in camera, microphone, and speakers. See Use the built-in camera.