My screen blank when im using speaker mode.

After disabling the below-mentioned option, check the camera with your Zoom meeting.

1. Open the Settings page in Chrome Browser:
Click on the three dots symbol in the top-right of your browser, then select Settings.
Or, type chrome://settings in your address bar and hit enter.
2. Scroll to the very bottom of the page and click on Advanced.
3. Scroll down further until you see System. Here, disable "Use hardware acceleration".
4. you might be prompted to relaunch Chrome.