Too bad. But if they don't want to provide oauth, they should take down the documentation. It's misleading.
OAuth does work but mainly for a narrow use case.
Really? How can you use it?
As described here, but again, it's not meant to be used in the Itch app.
Oh yeah. But what I want to do is identify a user and let them increase their score, like in a real game. I guess itch is not the platform for that.