Sign in to the Admin Center: Go to the Microsoft 365 Admin Center and sign in with your admin credentials.
Go to Users: Select Users from the left-hand navigation panel, then choose Active users.
Select the User: Find the user whose authentication methods you want to update and click on their name.
Navigate to Authentication Methods: Click on the Authentication methods tab.
Add or Change Methods: Here, you can add, change, or remove the user’s authentication methods (e.g., phone number, email). To add a method, click Add method, select the type, and enter the required information.
Save Changes: Once you’ve made the necessary changes, make sure to save your changes.
