This will help you duplicate or extend your desktop when using multiple computer displays.
Windows 11
1.Right click on your desktop and select Display Settings.
2. In the Display Settings, select Duplicate if you want your multiple screens to show the same thing or Extend if you want to extend your multiple screens.
Windows 10
1.Right click on your desktop and select graphics properties.
2. Select Display.
3. Select multiple displays.
4. Select Clone Displays.
5. Be sure to click on the Apply button at the bottom right.