Change Your Method for 2 Factor Authentication for MS365

Once you have setup your office.com account to pair with you mobile device you can then manage which method you want to authenticate with.

To change the method or add an additional method, login into your office.com account in a browser on a computer.

Click on your initials in the upper right corner:
Click on View Account
Go to Security info and click on Update Info
The following window comes up:
Click on Add Method and you will see this window. Click on Choose a method and the following methods are available:
You can add email address or and alternate phone.