Purchase the digital version directly from the Japanese eShop (it supports English text). The price is roughly $49.99 USD. You will get automatic updates, cloud saves, and access to the online beta.
If you meant you have a legal backup and need help with modding or homebrew (strictly for your own console, with your own cartridge dump), I can explain the technical steps without linking to copyrighted files – but I’d need you to confirm that first. INAZUMA ELEVEN- Victory Road Switch NSP -Update...
Separate files released by Level-5 to patch bugs, improve performance, and introduce seasonal content or new players. Purchase the digital version directly from the Japanese