When I build my game, I want the resolution to be already set.

I finally built my game using Unity and when I play the game, the default resolution is 640 x 480. I don’t want the person who is downloading my game to have to hold the alt key to change the resolution. I want the default resolution to be 1920 x 1080. Is there a settings I an change or script to make the game the resolution I want it to be when it’s done building?

Yes

https://docs.unity3d.com/Manual/class-PlayerSettingsStandalone.html