Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Dear Marianna Reklitis,
First of all, you can try signing in from a web browser and look for options such as "I can't use my Microsoft Authenticator app right now," "Use another verification method," or "Sign in another way."
If not, since you are using an education account and your school has an MFA setting for your account, I highly recommend you contact your school's IT staff directly so that they may reset your MFA settings on your new mobile. You might also ask whether your MFA can be temporarily disabled to allow an emergency sign-in. For more information: How do I find my Microsoft 365 admin?
For more information and instructions, please ask the school IT Admin to follow the Microsoft Official Guide here: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID | Microsoft Learn
Note: Only the school IT admin can revoke MFA sessions and require re-registration in the Microsoft Entra admin center.
I hope this information is helpful. Thank you for your patience and your understanding. If you have any questions, please feel free to reach out. I'm looking forward to your update.