i have a tmobile account that is attached to my outlook email address that i did not

I have an T-Mobile account attached to my Outlook email all of a sudden from an old Apple iPhone 11 that I turned on recently and they morphed together, but they will not recognize each other so one holds an iCloud with everything else the same same Google accounts outlook accounts, but will not accept the iCloudI did not put the T-Mobile account on my Outlook email. I’m wondering where it came from and how it was able to do, so does anybody know where has anybody had this problem before?