Q. I was asked to enter the authentication code, but I have not set the two-factor authentication. I entered and sent the authentication code, but it became an error. What should I do?

From the viewpoint of security, there may be cases where we require two-factor authentication to log in. Note that the error may be caused by any of the following reasons. Please confirm.

• If the sent authentication code is outdated
  When the authentication code is sent more than once, only the last one will be valid.

• If there was an error when entering the authentication code

• If 30 minutes or more has passed since the authentication code was sent
  The authentication code becomes invalid after 30 minutes or more has passed after it was sent. In such case, please have the authentication code sent again.

＜Related questions＞
Q. How do I have the authentication code sent again for two-factor authentication sent via email or SMS?