Can't find a way to cancel.

Hello, this is probably a dumb question but I have a PC Game Pass account, I want to cancel my account but for the life of me I can't log in.
I have my profile name but where the hell can I retreive the email adress or way to login to my account to cancel it?

Of course they made it so that it's not just enought be logged into the Game Pass app, no, I need to really login to the MS account.

So I go to profile, settings, subscriptions, then managing. Then I haave to login with an email or a phone number but I can't remember the email and can't find it in the Game Pass App.

Anyone who knows a trick?