I can't open a game becuz of the format help me plz

Hello guys , I m French and I try to use citra on Mac , there is a problem I downalded MH3 (game) decrypted but when I open it it says that the format is not supported but I used the same site Mod Edit: Snipped that they show in videos on youtube plz help me

@Walirus, Citra doesn’t support downloading pirated ROMs. Citra only works with decrypted .3ds files. If it’s a decrypted .cia file, it needs to be installed in the emulator.

is there a way you can get a cia file. Or any links?