Too late to help you, but how did you go ?
Technically according to the physical requirements when you sign up for an exam the below would apply:
- You are only allowed to use one screen during your exam. A larger screen is recommended as you must navigate multiple windows in the exam environment.
- Erase whiteboards, turn off televisions and monitors, and take down anything that may appear to have information helpful to taking the test.
Assuming you could completed turn off your laptop display so that just was used as webcam feed this may work, but tbh I wouldn't chance it. I've heard that by the [enable ability to] 'control your computer' in the exam requirements, this actually means they load temp software on there to check that you're not running anything you should (recordings, chat, etc.). Part of this may be a driver check to verify you don't have more than one monitor accessible, even if it's "off".
I wouldn't chance it. I recently took an exam to recertify, and bought an external webcam specifically for the scenario you're describing.