To protect your account, we’ve added a new layer of security with Google Authenticator (Google 2FA)

All users have passwords to their accounts, but passwords alone aren’t safe.  The passwords can be easily stolen. For this reason, we require users to use Google Authenticator and bind the Google two-step authentication to their account.  Once users accounts are bound, even if their password is stolen, the user’s phone or secret key is still required to log in to the account.

The Google two-step verification code is generated by the Google Authenticator on the phone, and the verification code is changed every 30 seconds.  Each verification code can only be used once.