Hello, thank you for reaching out to Microsoft Q&A.
Could you please check if you have enabled permissions for your default Windows Camera App?
Go to Start > Settings > Privacy & Security > Camera.
Ensure ' Camera Access' is enabled, and under 'let apps access your camera', ensure the Windows Camera toggle is enabled.
If you are still having issues,
Type msinfo in the search bar on the taskbar and click Enter.
Post a screenshot of the resulting dialog box.