Open any app that uses the camera, such as FaceTime, Photo Booth, Zoom, or Microsoft Teams
Launch Photo Booth from Applications or Spotlight search
Launch FaceTime from Applications or Spotlight search
Open Zoom or another video app and start a new meeting or test video
Allow camera access if prompted in System Settings > Privacy & Security > Camera
Check the camera indicator light near the top of the MacBook screen
Use the built-in camera automatically when the app starts video
Close other apps that may already be using the camera if it does not open
Restart the MacBook if the camera still does not work