This function is restricted, if the registered age at the start of the game is underage.

[Note]
Minor / Underage players will not have the option to [Change Player Name]. Several features are restricted based on the date of birth entered upon account creation. It is not possible to change the age of an account once it has been created. After the registered age on the account reaches the age of majority, these features will become fully accessible. We apologize for any inconvenience caused.