Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hi Rica,
Thank you for posting. You may refer to the article and follow the instruction under Turn on phone sign-in for work or school accounts to check this issue.
For your reference: Set up the Microsoft Authenticator app as your verification method
If you still having problem, then please contact your Office 365 administrator to disable and then re-enable the MFA setting to troubleshoot this issue.
If there is anything unclear, please feel free to let us know. We will be glad to help you.
Best regards,
Shyamal