How do I add an email to my Microsoft Authenticator app when I keep receiving the error message of Too Many Requests

Question

I had an email that was associated with my graduate school that was linked to my Microsoft Authenticator app. My email ******@syr.edu was closed last summer since they discontinued alumni having access. I tried to associate my ******@hotmail.com email to the authenticator app and I receive the message, 'Too many requests". I receive this same message when I try and sign in to my Xbox that runs our family entertainment. I even chatted with a Microsoft customer service rep under case 7077195861 that stated that I need to come to this forum and request assistance. Any assistance would be greatly appreciated.