You need the base NSP, the update file, and the DLC files.
Managing your collection of tracks in Theatrhythm Final Bar Line theatrhythm final bar line switch nsp update dlc free
The Switch version is particularly popular because of its portability. You can grind for summonstones or perfect-chain a track like “One-Winged Angel” on a morning commute. You need the base NSP, the update file, and the DLC files