According to the game's promotional materials, including the box cover and official marketing channels like Nintendo's YouTube promotional video of the game, the game is supposed to include the Super Mario Mash-Up pack with around 40 character skins.

However, upon installing and updating the game to the latest version, I found that the skins are not available. I have thoroughly checked the game and verified the installation, but the issue persists.

After researching this problem on various forums, I discovered that this is a widespread issue affecting many players around the world who purchased the game.

I kindly request your assistance in resolving this.