How to make a window invisible when sharing a screen?

Question

Google Chrome

The time is approaching when you have to take tests and exams, now they are taken remotely, in the asynchronous proctoring mode, when teachers check the video of a student taking a certain test and screen sharing is enabled. So, dear experts, the question is: HOW to make a certain window invisible when sharing the screen , so that it is not noticeable that a person googles questions or communicates with a friend? Broadcast with subsequent recording will take place through the Google or Yandex browser.

Answer 1

Show the screen of a virtual computer created through Oracle VirtualBox. It will work 100% .
On a physical computer, open whatever you want :)

Answer 2

Second laptop!
Or a second/external monitor, broadcast one, chattag on the other. But it will display the mouse cursor.

Answer 3

Move the window to the second screen, use the second device for Google