How to Adjust Fullscreen/Aspect Ratio?

Hey all,
Currently, I have my game aspect ratio set to 2160x1080. Since I have a 2:1 phone, this is fine for me. However, I’d like any device to be able to fit the screen. What I mean is that if a screen is bigger/smaller, I was the entire screen to be covered without distorting the game. For example:
(Smaller phone)

(Bigger phone)

The game stays the same, but the background fills the whole screen. On my pc, it seems to do this when fullscreen is activated:

Here in the game setting > properties you can handle that.
(I’m talking about the fullscreen/game size mode)

You can either tell the game to change it’s height to fit screen or width. Like this your game won’t distort.