Mac has increased their security features with the release of OS X Catalina. Not following these steps before your starting exam will result in technical issues.
Click the Apple Icon
Open System Preferences
Open Security and Privacy
On the left, scroll down and click Screen Recording
Click the checkbox next to the browser you're using - either Chrome or Firefox
You will be prompted to Quit Now in order for changes to take affect. Do this before your exam time
Note: There may be additional steps needed to allow ProctorU remote access, however, those can not be completed until the time of your exam. The steps above are for a successful connection before you're with a proctor.