If you are installing the Screen Capture extension on Chrome for MacOS and get an error that your computer or system denied screen sharing permissions, you need to give Chrome permission to share screen.
Please follow these instructions to grant those permissions:
1) Go to your Applications folder.
2) Open up System Preferences.
3) Go to Security & Privacy:
4) Once in Security & Privacy, go to the Privacy section:
5) In the left column, go to Screen Recording:
6) Finally, add Google Chrome to the apps that you want to give screen capture permissions to by checking the checkbox next to it:
You might need to click the lock icon (circled above) to make changes.
7) Restart Chrome for your permission changes to take effect.