There are several things you can try to fix a camera that's not working on your Android device:
Restart your device: This is the first step you should take when your camera isn't working. Restart your phone to clear any software glitches that may be causing the problem.
Check if the camera app is up to date: If the camera app is outdated, it might not work properly. Check the Google Play Store for any available updates.
Clear the camera app cache: Clearing the cache of the camera app can help to fix the problem. Go to Settings > Apps > Camera > Storage > Clear Cache.
Check for software updates: If your device is not up-to-date, it might cause issues with the camera app. Check for any available software updates and install them.
Remove any third-party camera apps: If you have any third-party camera apps installed, they might be causing conflicts with the default camera app. Try uninstalling them and see if it fixes the problem.
Check camera permissions: Ensure that the camera app has permission to access the camera on your device. Go to Settings > Apps > Camera > Permissions > Enable Camera permission.
Test the camera in safe mode: Sometimes third-party apps can cause issues with the camera app. Boot your phone into Safe Mode and see if the camera works. If it does, you might need to uninstall recently installed apps.
Factory reset: As a last resort, you can try a factory reset. This will erase all data from your device, so make sure you have backed up your data before doing this. Go to Settings > System > Reset Options > Erase all data (factory reset).
If none of these steps work, you may need to contact your device manufacturer or a professional technician for further assistance