Sorry for the late reply here.
I would like the main question on everyone’s mind responded to first: when you say you “signed up for Brave” what do you mean? Can you provide me exact steps you used to “sign into” Brave? We have an account for premium services, but that requires you go to a website and actively create an account but I don’t think this is what you’re referring to.
This feels like a very key part of this issue but its very unclear what you’re referring to given that, as others have said, you can’t “sign into” Brave as there is no “base” Brave account to use the browser.