To use the Booster Course Pass, you must own the base Mario Kart 8 Deluxe game. You can acquire the DLC through two primary methods:
Ensure your software is updated to the latest version (Ver. 3.0.1 or higher). Download File Mario Kart 8 Deluxe [DLC] [010015...
If the content doesn't appear, visit the eShop, select your profile, and go to "Redownload" to trigger the DLC install. To use the Booster Course Pass, you must