[spunk.funk]

Press the Windows key +X and choose Device Manager. Expand Imaging Device. Is you camera listed here? Is there any devices with yellow marks? Especially under Universal Serial Bus Controllers? if so this device needs drivers from the manufacturers web site.
If your don't know the manufacturer, right click the device with the Yellow mark and Uninstall it. Then Unplug the USB Camera and restart your computer. Once the computer loads, plug the camera into a different USB port, preferably a USB port in the back of the computer and not the front (Desktop) or thur a USB Hub as these ports are weaker. You should get the New Hardware Wizard and it should install. If that doesn't work it may not be compatible with Windows 11.

 

[spunk.funk]

I do not know what the dialog box is saying in Webcam Test because I don't speak that language.
What is the Make and Model # of your USB Camera?
Go to the Start Button in the Windows Apps choose Camera. If it still says that another app is using the camera, Restart the computer
It looks like your USB camera has the image reversed. Go into he camera's setting and change it to Front Facing Camera. If you don't know how, go to the manufacturers web site and download the manual for your camera.

 

[spunk.funk]

To test your camera on the WebCAM Test web site, you have to click Allow permission. I am not sure what the Bigger Problem is? You don't want to allow the use of the Camera?