Need help!

Can anyone explain what to do with the university mailing I'd? As I am directly logging in Gmail and it's showing I'd not found. Then I logged in to Microsoft365 and registered my phone number and email id, and after that I opened Ms word and there I logged in with my personal gmail and it says to buy the subscription. Then I tried with the university Mail and nothing happened. I opened microsoft365.web there after logging in, it says "your I'd isn't registered, admin need to activate it." What's the work with that piece of shit? Please explain me how to use university mailing I'd in brief.