Nintendo eShop
How to redeem your Nintendo eShop gift code:
On your Nintendo Console:
From the main menu, select 'Nintendo eShop.'
Scroll down to 'Enter code.'
Enter the 16-digit gift card code, which can be found in your transaction history on Razer Gold and in your purchase confirmation email, and click 'OK.'
The gift card funds will be added to your account. Now when a game catches your eye, all you need to do is select it and complete the purchase!