Multifactor Authentication using Microsoft Authenticator App
Step 1: Using your SDN email credentials, sign on to the My Microsoft Account portal.

Step 2: Select Security info in the left menu.
If you have set it up already, You'll see the Sign-in Method on the list.
If you don't have any item --OR-- if you would like to add a new/alternate Sign-in method, click on "Add sign-in method" option, select the most suited method(s), and follow the instructions on the screen.

Step 3: On the Add a method page, select Authenticator app from the list, and then select Add. On the Start by getting the app page, select Download now to download and install the Microsoft Authenticator app on your mobile device, and then select Next.
Step 4: Remain on the Set up your account page while you set up the Microsoft Authenticator app on your mobile device. Open the Microsoft Authenticator app, select to allow notifications (if prompted), select Add account icon on the upper-right, and then select Work or school account.
Step 5: Select Next on the Scan the QR code page on your computer. A notification is sent to the Microsoft Authenticator app on your mobile device, to test your account. Press Next when you are done.