This article describes the steps to setup set up the Alternate phone method of authentication.

Step-by-step

Tip
The Alternate phone method allows to receive a call at your phone. This is helpful for situations where you want to add an additional phone other than the one you setup in the Phone or Office phone options.

Open up a browser and go to https://mysignins.microsoft.com/security-info.
Login using your SSD username and password.
Click the Add sign-in method button.
Select the Alternate phone method from the list. Click Add.
Enter your 10-digit number (no special characters. e.g., 3145172917)
Answer the call and follow the prompts.
If you followed the prompts correctly, you will be prompted with a success screen. Click Done.
Now you may use this MFA option when logging into your SSD account.