Two-Factor Authentication (2FA) or Two-Factor Authentication (TFA) is an additional layer of security that is known as "multi-factor authentication" which requires not only a password and a username, but also something that only the user has on them, for instance, a piece of information only they know - such as a physical token which automatically changes every minute. Click here to know how you can set up 2FA.
Here at Bitkub, enabling 2FA authentication provides the 2nd layer of security to your account before you log in, change your password, trade, and withdraw. This prevents unauthorized access from other users who have your login password.
Google Authenticator provides a six-digit one-time password that resets every 30 seconds using the Time-based One-Time Password algorithm (TOTP) and HMAC-based One-Time Password algorithm (HOTP).
For your reference, you may check these links if you have trouble with your 2FA: