Hello @Esther Ivinizki,
Thank you for posting your query on Microsoft Q&A.
Based on your description, I understand that you're unable to access the application because you're not receiving the OTP on your registered mobile number to complete the second factor of authentication (MFA).
It's possible that your registered MFA method has been revoked. To resolve this, please contact your global administrator and ask them to reset your MFA by following these steps:
- Sign in to the Microsoft Entra admin center as at least an Authentication Administrator.
- Go to Identity > Users > All users.
- Click on Authentication methods and select Require re-register multifactor authentication.
The next time you try to log in to Azure services, you will be prompted to register for MFA again.
For more details, you can refer to this guide: Manage user authentication options
I hope this information is helpful. Please feel free to reach out if you have any further questions.
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Thanks,
Raja Pothuraju.