Hello! Anuki M
Welcome to the Microsoft community.
I understand that the current situation is that you are unable to log in due to the unavailability of an authentication account.
After diligent investigation, I can safely say that your knowledge in this area will be broader than mine.
The most appropriate community for posting your issue should be Microsoft Authenticator - Microsoft Q&A, which is a professional place made up of many technical experts or advanced users like you.
Also, I'll keep this thread open in case our volunteer MVP/moderator/ can have some targeted insights for you.
Thank you for your understanding and cooperation.
I wish you a peaceful life.
Celia | Microsoft Community Support Specialist