Two-factor authentication creates an additional step to the login process where you will be requested to provide a one-time passcode to access the portal or Management Console (this is dependent on your portal settings).
If you have not received the one-time passcode in your email inbox, first confirm that the registered email displayed on the one-time passcode screen is correct. If it is not, contact your company administrator or your Customer Success Manager email@example.com
If you have received the one-time passcode, and it is incorrect this may be because it is no longer valid. You can require a new one-time passcode by selecting resend code again.