To redeem your code, go to marvel.com/redeem and enter your 12-digit code in the field next to the blue "Add to Cart"" button. If your code is valid, the redemption process will continue. As part of the process, you will need to create a Marvel account or sign in with an existing account. Then, you'll be asked to provide the name of the store where you bought your print copy. Once you've provided the name of your retailer, you'll be able to claim your bonus digital comic.