How NOT open window in full-screen?

The web page wants to open the window in full screen and does not allow you to use it How to open a web page in a window, but so that the web page thinks that it is open in full screen? I use selenium. example: https://play.geforcenow.com/games?game-id=717c2b0e-b37a-45ef-95e6-b7cbd656430f&lang=ru_RU&asset-id=01_134b5e2b-2d46-4433-896e-a9de5de731e8