camera doesn't work on 2016 MacBook pro 13"

Check to see whether the camera hardware even appears in the Apple System Profiler. Option-click the Apple menu and select the first item. Click on "Camera" on the left pane to see if the hardware information for the camera is displayed on the right pane. If it does not show any hardware information, then the laptop has a hardware issue of some sort. You will need to have Apple or an Apple Authorized Service Provider examine the laptop to provide you with a repair estimate.

If the camera hardware is listed, then try using Photo Booth to see if the camera works. If it does not, then try creating a new macOS user account. Log out of your current user and log into the new user account. Try using Photo Booth again. If it now works, then you have some sort of configuration issue with your main user account. If it still fails, then you can try reinstalling macOS over top of itself. Normally I would first suggest booting into Safe Mode to try the camera, but I have seen Safe Mode disable the camera sometimes, but it may still be worth a try because if the camera works in Safe Mode, then it indicates an issue with a third party app.