To play legally owned games, users must "dump" (extract) these system keys directly from their own 3DS hardware and save them into a text file named exactly aes-keys.txt . Where the Keys Live
Citra needs the "aes-keys.txt" file to decrypt and play 3DS games. Without these keys, the emulator cannot properly decrypt the game data, resulting in errors or crashes. The file helps Citra to: aes-keys.txt citra
To help you get the right keys, are you able to use a , or are you trying to find a pre-made aes_keys.txt file? To play legally owned games, users must "dump"