To activate a Nintendo Switch game key, you need to redeem the 16-character download code on your Nintendo Account. There are two ways to do this. On Nintendo Switch: open the Nintendo eShop from the home screen, select your account, scroll down the left sidebar and select Enter Code, enter your 16-character code and select OK. The game will be added to your library and begin downloading automatically. On a web browser (PC, phone, or tablet): go to ec.nintendo.com/redeem, sign into your Nintendo Account, enter your code, click Next, confirm your password and click Redeem. The game will be available to download next time you open the eShop on your Switch. Important things to know:
Nintendo game keys are region locked — the code must match the region of your Nintendo Account
The letters I, O, and Z are never used in Nintendo codes — what looks like one is actually a number (1, 0, or 2)
Each code can only be redeemed once — once activated it cannot be used again on any other account
The Nintendo Switch Online mobile app does not support code redemption — use the console or web browser only