Hi @Steven Frame ,
I'm sorry that you are experiencing such problem to sign in to Azure Portal.
If your issue is exactly the same as the other post and you are on a Tenant Lockout scenario, which means that you cannot access either Azure Portal or MyAccounts in order to register for MFA, the recommendation would be the same and you'd need to open a support ticket with our Global Customer Service team, or you can contact the Azure Data Protection team for further assistance - (866-807-5850).
Let me know if you have further questions.
Thanks!