You will need to be assigned the Global Administrator Role in order to complete these steps, we can only assign this role to the account holder or the account holder can request another user by raising a support ticket
Step 1
Go to https://portal.office.com/
Step 2
Enter your Global Administrator Email Address and click Next
Step 3
Enter your Password and click Sign in
Step 4
Click Yes to stay signed in
Important Note: If you are asked to either sign in with Work or School Account or Microsoft Account, Please select Work or School Account
Step 5
Click the waffle icon (Nine Dots) then click Admin (If admin isn't listed click All apps)
Step 6
Click Users
Step 7
Click Active Users
Step 8
Click Multi-factor authentication
Step 9
Tick the box next to the user you want to enable MFA on
Step 10
Under quick steps click Enable
Step 11
Click enable multi-factor authentication
Step 12
Clock close
When the user next signs into Office 365 they will be asked to set up MFA for their account