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- If you get a new cellphone, the best thing to do is to you will want to navigate here, https://aka.ms/MFASetup and delete the account that shows up in the Microsoft Authenticator app (probably it ill will say Azure AD) and also the device from https://aka.ms/MFASetup and to follow these steps to reset the appas well.
When you open the app, make sure to enable notifications from the app!
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