Running custom or backed-up NSP files requires a modified Nintendo Switch console. Standard, retail consoles cannot execute these files natively. Prerequisites

Downloading NSP files for games you do not legally own is a violation of copyright law and constitutes digital piracy. Nintendo fiercely protects its intellectual property. The only legal way to obtain an NSP file is by using custom firmware to "dump" a game that you have rightfully purchased from the eShop or a physical retail store. The Threat of Malware and Bricking