All juniors (under 18s) must be linked to a Parent/Guardian FAN. You can check to see if you have a FAN already here.
If you cannot find that you already have a FAN, you can create a new FAN here.
After creating your personal FAN, please then navigate to 'My Account'. Here you will find the option to create and then link a Junior FAN to your account. You can do so by following the instructions and inputting the requested information on screen.