If you are unable to share your screen in Google Meet, follow the directions below to enable this option. 

1. Open System Preferences by choosing the Apple menu in the top left corner of the screen. 

2. Choose Security & Privacy

3. On the Privacy tab navigate to Screen Recording and ensure that Google Chrome is checked. 

4. Close System Preferences

5. Quit Google Chrome by clicking Chrome > Quit Chrome

6. Relaunch Chrome and rejoin the Google Meet. You will now be able to share your screen.