How to extract gba save from virtual console

Hi, I want to play a pokemon rom hack "pokémon éclat pourpe" on my 3ds. I have try with mgba but it was running so badly. I injected the game on my 3ds after converting the .gba to .cia and the game is working really good. But I also have a hacked switch and it would be nice if I was able to get my save from my 3ds and being able to switch of device by time to time.

So how am I supposed to extrat saves from the romhack ?
I have try JKSV but..

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I have try fbi but..

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I'm trying right now, I have click on "update cache (auto)" and i'm waiting to see the result



edit : It is working ! Thanks