Hi,
If your issue concerns Microsoft's account, please check on the security page if you have configured the correct sign-in verification option(s).
https://account.live.com/proofs/manage/additional
This document will help you: https://support.microsoft.com/en-us/account-billing/change-your-two-step-verification-method-and-settings-c801d5ad-e0fc-4711-94d5-33ad5d4630f7
If the issue relates to a work account, please refer to the Security Information below.