Hello Eliel Henao,
Thanks for your question
To migrate your authenticator, you first need to back it up. Since this was not done, you need to do the following:
First contact the School IT admin, they can reset MFA for your account and to re-register for MFA.
They simple need to go to your account in entra and re-require MFA.
If you have other accounts e.g socials you need to contact their support teams
If you can't reach out to the admin, it becomes a bit more complex as u dont have access to the app anymore, the only way to resolve this is to request for Product Support to reset MFA for the affected user for microsoft accounts. Contact Product Support with the email address for the affected user. https://azure.microsoft.com/en-us/support/create-ticket
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,