I honestly just watched a youtube tutorial

You probably can look into the arch wiki although if you don't use arch there may be some differences.

If i find the youtube video i will edit this comment and link it [here]

Alternatively here is how i did it:

•Install the bottles application (from the aur) •install proton ge runner •Create a new bottle •select proton ge as runner for said bottle •Download launcher installer (battle.net in my case) •run application > battlenetinstaller.exe (or however it's named)