As of late March 2023, it will no longer be possible to make purchases in Nintendo eShop for Nintendo 3DS, including add-on content for this game. For more information please visit Support.
Offers in-game purchases

Go clubbing around the world with Mario™! Tee off as your favorite Mario or Mii™ character while challenging players online. Shoot into warp pipes and dodge piranha plants in Mushroom Kingdom areas or take a shot at the nature-themed courses.

Power-up your shots with special items to burn past pesky plants, blast over gaping chasms, or freeze water hazards. The new Castle Club has both naturalistic and Mario-themed courses, a training area to hone your skills, and a pro shop where you can get unlockable gear and outfits.

Test your skills in a gauntlet of course challenges, play with friends locally
(using emoticons to cheer them on), or take on players around the world in online real-time tournaments.