1. Open the Nintendo eShop on your Switch console.
2. Select "Redeem Code" from the eShop's main menu.
3. Enter the code you want to redeem and confirm the input.
4. The game or content will be automatically added to your library and can be downloaded and played.

Make sure you enter the code correctly to redeem it successfully. If you have any further problems or questions, please feel free to contact us.