Synopsys:

Use the steps below to switch the Microsoft Authenticator to your new phone

  Steps to complete:

Please go to Microsoft Office Home
Click on your picture profile on the top right, then click on “View Account”.

Click “Security Info

o If you are receiving a code via text message for authentication, just click “change “to enter your new phone number and you are done.

o If you are using the Microsoft Authentication App, then click Delete and click on Add method. CONTINUE WITH THE STEPS BELOW

You will see the popup below. If you have the Microsoft Authenticator App already downloaded then click Next, if not just download it on your iPhone and click Next

Allow Notifications if prompted on the phone.
Tap on Add an Account and select “Work or School”.

Click Next on the computer

On your phone tap “Scan QR Code”
Scan the QR Code that appears on your computer using your phone.
Click Next

You will receive a notification on the app. Click approve on your phone.

On your computer, click Done.

You will be asked to add your Work phone number in case mobile app stops working.

Enter the mobile number and click done.