Multi-factor authentication means you and your employees must provide more than one way to sign in to Microsoft 365 is one of the easiest ways to secure your business.
1. Login to the Admin Center
2. Select the Hamburger icon from the top left.
3. Select Show all
4. Select Identity from Admin centers
5. Select Properties
6. Click on Manager security defaults at the bottom
7. Under Security defaults, select Enabled and click Save at the bottom
Next time the selected employees sign in, they'll be asked to set up the Microsoft Authenticator app on their phones for a second form of authentication.