My game is really intended to be in a fixed, vertical shape of screen. Is there a way to specifically force the game into a certain ratio and prevent the player from stretching it?
Canvas always have “Canvas Scaler” that have options Scale with ScreenSize.
And Set Canvas Render mode to Screen Space - Camera
Also in the File> Build Settings there are options for PC, iOS, android, etc that allow you to lock aspect ratios, fullscreen, portrait, landscape, etc.