Close the game window through the exit cross

[sriyash421]

[mondalshubham1]

please clarify which keyboard key to be used.

[arnav-t]

@mondalshubham1 He means the 'X' on the top right of the window. This issue might not be fixable for now as it seems OpenCV doesn't support this.
On the other hand, pressing escape to exit has already been implemented.