@Anonymous Welcome to Microsoft Q&A Forum, Thank you for posting your query here!
Based on your error message: AADSTS50020 - User account from identity provider does not exist in tenant. This article helps you troubleshoot error code AADSTS50020
that's returned if a guest user from an identity provider (IdP) can't sign in to a resource tenant in Azure Active Directory (Azure AD).
You should be able to sign by using both https://portal.azure.com as well as https://azure.microsoft.com.
There is also similar threads discussion in the SO forum, please refer to the suggestion, which provides some idea on your scenario
Additional information: [https://answers.microsoft.com/en-us/msoffice/forum/all/identity-provider-livecom-does-not-exist-in-tenant/f9897b40-94aa-43da-b7a3-5df7a5717acb
[https://learn.microsoft.com/en-us/answers/questions/209254/identity-provider-live-com-does-not-exist-in-tenan
Please let us know if you have any further queries. I’m happy to assist you further.
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