Hi Rahel (beckrah1)"),
Thank you for reaching Microsoft Community. We're sorry for the trouble this has caused you. Let me ask few questions to help us further isolate the issue.
Could you please clarify whether you mean the built-in camera or external webcam?
Did you use a web browser or the application?
May I know what version of Windows are you running?
Check your app permission. You might need to change one of your device's permissions.
Open Settings > Privacy and Security > Camera. Make sure Camera access and Lets apps access your camera are both turn on. If the settings are already turned on, turn the settings off then back on again. Choose which apps should have access. Only apps that were installed from the Microsoft Store will appear on this list.
If you're having problems with an app that you did not install from Microsoft Store, make sure that Let desktop apps access your camera is turned on. You can't turn off camera access for individual desktop apps. Internet browsers, like Microsoft Edge, and many video conferencing apps, like Microsoft Teams, are desktop apps that require this settings to be turned on.
If you're using the Zoom and Teams applications, you may try to uninstall and reinstall both apps and see if problem persist.
I hope to hear back from you.
Kind regards,
Lavenia