Resizing both height and width

I’m making my first game, I plan to make my game resolution 360x640 (9:16) but my phone’s resolution is 540x960 which is also 9:16 aspect ratio, but I do not know what settings to use, In the properties settings, it only has the option to adjust to width or height but not both, are there other settings I should look into?

These width/height settings are useful to fill the gaps (black bars) when the ratio is different.
If the ratio is the same, I think the game will zoom in/out as needed.

If you choose the action “Activate Fullscreen” then the game will fill up whatever screen size it’s on and maintain it’s aspect ratio. Any difference will be filled with black bars.

Changing the width or the height to fill the screen in the properties settings means your game will change it’s aspect ratio to fill the screen (either taller or wider).

So, if you want to keep your game in the 9:16 ratio you made it in, then choose the first option. If you’re more concerned about your game filling up whatever screen size it happens to be played on, then choose the second option.