Check this out https://gbatemp.net/threads/r4-stage2-twl-flashcart-launcher-and-perhaps-other-cards-soon™.416434/
Edit: looking at it more closely, the flashcard should be 3ds compatible... maybe the flashcard is faulty or the flashcard does not make contact with the pins correctly? (wonky flashcard?)
Im completely new to the R4 world, could it be that i dont have the proper programs or thet the ds card is not properly formatted? Its good to know that atleast its real tho.