Hi,
Thank you for your question and for reaching out.
I understand that you're having sign-in issues on your Work or School account. If the system is not detecting your email, this only means that it is not registered on the Microsoft database. It is possible and quite confusing.
The resolution for this is to know if it is really registered. To check, log in to this link https://account.microsoft.com/, and if it is successful, then there might be something wrong with the setup configuration in settings. On the other hand, if it gives you an error like "No account found", then it is NOT registered on the database, and you have to contact either your Company or School and ask them more about it. They should be able to help you set up the account properly that way.
If the reply was helpful, please don’t forget to upvote or accept as answer, thank you.