For standard, unmodded consoles, updates are handled directly through Nintendo's servers :
You must install the base game NSP first, then the update NSP separately. For emulators, use the "Install File to NAND" option for both files. Merging Files: To simplify the process, you can use tools like NSC Builder SAC (Swiss Army Knife) mario vs donkey kong switch rom nsp update work
Are you running the game on an or a modded Switch console ? mario vs donkey kong switch rom nsp update work