Need help getting this going

[FerelBasta]

Hello, I just got an R4 card to be able to use pkmn-chest to move pokemon between my gba games, but when I installed the .nds file onto the card, it says theres this error "nitroFSInit()failed..." and such. I looked everywhere to try and fix this but nothing has come up, I tried renaming the file to sd:/_nds/pkmn-chest/pkmn-chest.nds. since it doesn't go into detail on where this needs to go and it says I'm not allowed to do so. I did some further tweaking and then got the error of needing fat:/_nds/pkmn-chest/pkmn-chest.nds. I have zero clue where to copy the .nds file too and I can't name a file this. I somehow managed to get this to boot ONCE but then I ether get the same error screen or just a black screen. I honestly am very lost on what to do and I feel like I'm getting nowhere with getting this to work right, I tried putting it in the twilightmenu folder, the nds-hb-menu too but I still get nothing! Please if anyone can guide me step by step on how to get this to run smoothly and properly I'd highly appreciate it! <:3