One-Time Password called OTP is the password valid for only one use, mainly used for the purpose of logins or withdrawals.
If you wanted to enable or disable OTP, please move on to the OTP page.
(Select the [My] menu on the top of the main page → then click the [OTP Authentication] menu.)
※ Note : Do not forget to backup the 16 digit key irrecoverable just in case of losing it. Please keep it safe after OTP is enabled.