Need to Authenticate account

Hi hana

If you still have access to an existing authentication method, you may be able to update your security information through the Security Info page and add your new phone or phone number.

How to add your accounts to Microsoft Authenticator | Microsoft Support

• Visit the My Sign-Ins | Security Info | Microsoft.com page to manage your verification methods   
• Sign in with your work account. 
• Select Add sign‑in method > Microsoft Authenticator. 
• Install Microsoft Authenticator on the new phone. 
• In the app, choose Work or school account, then scan the QR code shown on the Security Info page. 
• Approve the test notification sent to the new phone. 

If you no longer have access to the previously registered phone number or Authenticator device, since your account is school account, it is managed by your school's IT department. Microsoft doesn't have direct access to reset authentication settings for organization-managed accounts. However, you can contact your organization's IT administrator and request a reset of your MFA settings by following this article: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID | Microsoft Learn

(Note: We're not Microsoft support, this is a user-to-user support forum. Moderators have no backend access and cannot directly intervene in Microsoft products. We provide only technical guidance and best-practice recommendations based on reported issues).

I hope this information helps and if you have any question, please feel free to ask via comment section,

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