When you purchase digital content, like a game or movie, from Amazon, you'll receive a confirmation email with the digital code. You'll find the code on either the Order Summary page or in the email's body.
If you didn't receive the code, check your Spam folder. If the code still can't be found, contact Amazon Customer Service at https://www.amazon.com/contact-us. Include order details and the email address associated with your purchase.
Once your code is located, you'll be sent instructions on how to redeem the code, which will depend on the type of product you purchased. Amazon has detailed redemption instructions for different products on the Digital Software A-Z page (https://www.amazon.com/gp/digital/az).