Step1: Sign in to Microsoft 365 Admin center with admin credential (https://portal.office.com) or directly go to your security info page (https://mysignins.microsoft.com/security-info)
Step2: Click on the Add sign-in method under Security info.
Step3: Click on the Phone sign-in method from the options.
Step4: Select the country code and enter the phone number, then click on the Next option to receive a code on that number.
Step5: Enter the 6-digit code received on the registered phone number and click on the next option.
Step6: Hence, the phone number MFA has been set up successfully to the registered mobile number.
