This article explains how to grant screen recording permissions to Mettl Secure Browser(MSB) on MacOS

1.  You'll see a prompt to grant permissions like the one shown below. Make sure you choose "Open System Preferences".

2.  After clicking "Open System Preferences" go to the Screen Recording section inside Security & Privacy.

3. Double click on the lock icon on left bottom to make changes.

4. Enter your password or Touch ID grant access. 

5. Click the checkbox next to MSB app icon.

6. Double click on the lock icon on left bottom to save the changes.