An NSP is a Nintendo Submission Package. It is the file format used by the official eShop. If you have a modded Switch, you can dump your digital copy of Tears of the Kingdom into this format to back it up or run it on PC emulators (Ryujinx / Yuzu).
[TUTORIAL] The Legend of Zelda: Tears of the Kingdom – Running your NSP dump (For Ryujinx/Yuzu) legend of zelda tears of the kingdom nsp
What mods are you running on your dumped copy? I just got the "Weapon Durability Remover" working on 1.2.1. An NSP is a Nintendo Submission Package
Nintendo Switch (CFW) / PC Emulation
This post is for educational purposes and assumes you have dumped your own legally purchased copy of the game. Do not ask for download links. legend of zelda tears of the kingdom nsp