To use this update on a modded Nintendo Switch, you need an installer like (highly recommended for simplicity) or Tinfoil . Using DBI (USB Install): Connect your Switch to your PC via USB. Open DBI on your Switch and select "Run MTP Responder."
This file is only an update (Update 1.0.3). It will not work unless you already have the base Digimon Survive game installed on your system.
Ensure your Switch's custom firmware (CFW) and system firmware are up to date. Newer game updates often require a minimum system version to run.
Are you installing this on a or an emulator ?
If you are using an emulator like Ryujinx or Suyu , you can typically install the update by going to File > Install File to NAND and selecting the .nsp file.
How to Install NSP Files from SD card to the Nintendo Switch using Tinfoil!!!