1. Sign in to your Paizo.com account (if you’d don’t have an account, you can set up a free one by clicking ‘Sign In’ in the top-right corner).
2. Head to https://store.paizo.com/redemption ot the Redeem a Code link at the bottom of store.paizo.com.
3. Enter the 16-digit alphanumeric code key in the box and click ‘Redeem’.
4a. Appicable items will be added to your cart. You can then check out with all appropriate discounts.
4b. Physical products will prompt you to input a shipping address and payment method (to pay the cost of shipping). If you run into problems during this step, please contact Paizo Customer Service at customer.service at paizo.com