Open an app that uses the camera, such as FaceTime, Photo Booth, Zoom, or Teams
In Finder, open Applications
Double-click Photo Booth to open the camera
Double-click FaceTime to use the camera in a call
Open Launchpad and click Photo Booth
Open Spotlight with Command + Space, type Photo Booth, and press Return
Open System Settings
Go to Privacy & Security
Click Camera
Allow camera access for the app you want to use
Check that the camera indicator light is on
Close other apps that may already be using the camera
Restart your Mac if the camera does not open
Update macOS if the camera still does not work