Hello Blind Guy,
Thanks for using the Apple Support Communities. We understand that you're running into an issue granting access to your camera and microphone for several different apps. Would you let us know which model Mac you have and the exact version of Big Sur you have installed? This is located by clicking the Apple Logo () in the upper left corner and choosing About this Mac.
There are a couple different actions you can try using to correct this issue.
First, restart the Mac. Choose the Apple Logo () in the upper left corner and select Shutdown or Restart. Once you've booted back up, go ahead and test again to see if you can provide the needed permissions.
Second, if restarting your Mac didn't correct the issue, check to make sure your apps are up-to-date, if any updates are available, go ahead and install them and test again.
You can also try booting into Safe Mode to test this issue as well. Safe Mode will do a basic check of your startup disk, similar to First Aid and may help correct this issue. How to use safe mode on your Mac Test the issue while booted into safe mode, and again after rebooting normally.
Best regards.