Log in to Microsoft 365, click your profile photo in the top right corner, and select view account. 

Please note: Before using the Authenticator app, Cartersville School System recommends registering a phone number for authentication. If you only use the authenticator app you may be locked out of your account temporarily if you lose or replace your mobile phone.

In the Security Info section, select Update Info.

The Security info screen will show your default method for sign in and list all methods currently connected to your account. As in the screen shot, you should already have a phone number associated with your account. Select Add method to register the Authenticator App.

Choose Authenticator app from the method drop down menu and click Add.

Download the app from the link on your screen or visit Microsoft's Authenticator App page for direct links to the Apple and Google Play app stores, or to get a download link sent to your phone.

Once downloaded, open the app on your phone and select Add Account.

Select Work or school account.

Select Sign in or Scan QR code (this tutorial shows the QR code method, but the sign in process is similar). 

After signing in or scanning the code, you will be prompted to approve the sign in on the app. Select Approve. 

You will see a confirmation message that the sign in has been approved. Click Next. 

Your Security info will update showing the Authenticator App is connected to your account. To make it the default sign-in option, click Change. 

Select Microsoft Authenticator - notification then Confirm. 

Your Security info page will now show that the authenticator app is the default sign-in method. Return to this page if you change devices or want to switch back to receiving text or phone calls for sign-in. 

Please note: You may be prompted to re-authenticate to multiple Microsoft 365 servers (e.g. Teams, Outlook, etc.).