Assuming you have legally obtained your NSP dump (via a cartridge you own and a homebrew dumper like NXDumpTool), here is the lab workflow:

: "NSP" (Nintendo Submission Package) is the official file format used for digital Nintendo Switch games.

This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. How to Update Game Builder Garage - Nintendo Support

The system will automatically download and install the latest patch. Local Wireless Method (Offline)

Follow the prompts to create a local group and sync the update wirelessly. Share public link

Press the + Button or - Button on your controller.

Always try to use official Nintendo updates if you are connected to the internet.