How do you find the card key in riddle transfer?

In "Riddle Transfer," the card key is found by solving various puzzles and riddles throughout the game. You need to interact with objects and characters, gathering clues that lead you to the location of the card key. Pay attention to hints given by NPCs and the environment, as they often provide vital information. Once you have collected enough clues, you can unlock the card key's location and retrieve it to progress in the game.