The only legal and safe way to obtain this game is through the official Nintendo eShop on your Switch console. To help you further, could you clarify:
Distributing, downloading, or using circumvention tools to install pirated games is illegal and violates Nintendo’s intellectual property rights [5.3]. RECALL Switch NSP (eShop)
Are you trying to or looking for a backup? Do you have a modded Switch console already? The only legal and safe way to obtain
is likely a reference to a specific indie title available for the Nintendo Switch. When looking for it as an NSP (Nintendo Submission Package) file, users are usually trying to find the eShop version for use on a modded console. Key Takeaways could you clarify: Distributing