Can't link AppleCare to my Apple ID
I'm clicking the link in the AppleCare receipt email, this is supposed to take me to my Apple ID My Support page so I can link the AppleCare plan. After attempting to log in using the OS' dialog window it loops back around to trying to login again. This repeats forever. If i cancel that and attempt to log in using an email and password I get an error message stating that access to that application is denied. I'm able to log in as normal with my AppleID and have no other account issues that I am aware of. Is there any other way to link AppleCare? I've been trying this on and off for nearly a year, foolishly thinking it might self-resolve.
Mac mini (M1, 2020)