2 pass verification fail

Question

I've tried to cancel office 365 subscription of another account "******@gmail.com".

However, my staff lost the password, so I have to reset the password.

First verification is getting the code from an email "******@gmail.com" has no issue; however, when sending the code to mobile phone, the error message kept saying "This authentication is not allowed" and I have to press back button and I cannot manage my account.

Regards,

Alex