If you have gotten a special code from one of our organizational partners, the code is entered on the bottom of the left side of the second signup screen after you have selected an account and before you enter billing information. See below where it says "Add" after "Have a Promo Code".
If you did not enter a promo code on this page, HAVE NO FEAR!!! (You can enter it on the next page).
Enter the code below the First Payment amount and above the Billing Address / Details. In this example, the screen reads "No Code Applied"... click "Edit" to enter the code.