Step1: Go to 'https://www.office.com'and login as usual
Step2: More information required popup and click 'Next' button
Step3: Keep your account secure popup and click 'Next' button after install Microsoft Authenticator apps on your mobile phone.
Step4: Keep your account secure pop up and allow the notification on your Microsoft Authenticator apps on phone. Then, click 'Next' button.
Step5: Keep your account secure pop up and show the QR code. Open your Authenticator Apps on your phone, and choose Scan a QR code and Scan the QR code. After scan, click 'Next' button
or.. If u already click skip on authenticator apps,
At home page, click '+' , then choose add 'Work account'
then choose 'Scan QR Code'
Step6: Keep your account secure pop up and show the number to try whether it success or not.
On your phone, notification "Are you trying to sign in?" will pop up. Enter the number and click 'Yes' button
Step7: Keep your account secure pop up and shows notification approved. Click 'Next' button for the next step
Step8: Keep your account secure pop up and enter your mobile phone for 2nd method. Then, click 'Next' button.