There is no charge in login creation krub. The license you are using allows multiple users to create their own login anytime. Please note that this is a "New Login" creation, not a change in existing login krub.
To create a new login, simply go to the login page and you will find a blue link to "create new login". Follow the few steps to complete the validation krub. You can also call 02-654-7300 anytime for further assistance.