Because it is an older title, Just Dance 2018 is often unavailable for direct digital purchase on the eShop:
: If you purchased a digital code from a retailer, you can redeem it on the Nintendo eShop to download the game files legally. Just Dance 2018 Switch NSP Free Download
Just Dance 2018 - Nintendo Switch : Ubisoft: Video Games - Amazon.com Because it is an older title, Just Dance