I just want a person to explain how to upgrade my camera from Catalina

Hi,

I suspect Catalina's bug, I mean driver's bug. You'd better contact Apple support or make Genius Bar reservation or take your MacBook Pro to Apple Authorized Service Provider to tell them about your camera trouble.

https://support.apple.com/contact

https://www.apple.com/retail/geniusbar/

https://locate.apple.com

I just wonder what do you mean upgrade camera?

You can't replace camera. If you want to better quality web camera, you should get high quality web camera which compatible with Catalina MacBook Pro like following.

https://www.amazon.com/Microphone-Multi-Compatible-Conference-Streaming-Recording/dp/B088F1PJZM/ref=sr_1_1_sspa?dchild=1&keywords=macOS+Catalina+compatible+web+camera&qid=1592572001&s=electronics&sr=1-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyQTRBWUZPUzNRRERTJmVuY3J5cHRlZElkPUEwODI2Njc1MTI0RzdaNEozT0cwWSZlbmNyeXB0ZWRBZElkPUEwOTk0MjM1RjRRQjFTQ0VQUzBWJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==