It sounds like you're experiencing a common issue related to multi-factor authentication (MFA) with the Microsoft Authenticator app. Since your account is linked to a third-party authentication app and you no longer have access to the verification codes, you will need to reset your MFA settings to regain access to your account.
Here are some steps you can take:
- Contact Support: Reach out to Microsoft support for assistance with resetting your MFA. They can help you regain access to your account by verifying your identity through other means.
- Use Backup Codes: If you were provided with backup codes when you set up MFA, you can use those to log in.
- Emergency Access Account: If you have set up an emergency access account (also known as a break-glass account), you can use that to access your account and manage your MFA settings.
- App Passwords: If your organization allows it, you might be able to use an app password to log in to your account without needing the MFA code.
If you are unable to resolve the issue through these steps, the best course of action is to work directly with Microsoft support to find a solution that works for your specific situation.