Camera don't work on iMac

hi everybody. I’m a newbie and I would like to try Jitsi but camera don’t work. I got a message telling me your device does not support the required video resolution.

I did a speediest and I got 7mB. I use a Mac with Catalina.
Does anyone have a solution?

Thanks

Hi. Some apps on Apple can have problems with camera if they were not installed from App Store.