Dear Daliah Mohamed & A,
Welcome to Microsoft Q&A.
I’m sorry to hear you’re having trouble signing in after changing your phone. When you uninstall Microsoft Authenticator from your old iPhone without transferring your accounts first, push notifications for approvals stop working because the app registration is tied to the original device.
Forum moderators have no control over user accounts, especially when it comes to logging in to your account, resetting your password, changing your access, etc.
If you're using a work or school account, please note that MFA settings are typically managed by your organization's IT administrator. In this case, we recommend contacting your admin to verify your MFA configuration or reset your authentication methods.
Please have your administrator follow the steps shown in the following article: Manage authentication methods for Microsoft Entra multi-factor authentication - Microsoft Entra ID …
If you need help finding your admin, please see: How do I find my Microsoft 365 admin? - Microsoft Support
I hope this information helps point you in the right direction. If you run into any issues while trying the steps, or if something still doesn’t feel quite right, please don’t hesitate to reach out again. I’ll do my best to support you however I can.
Looking forward to hearing back from you with any updates or additional details.
Warm regards,
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