If you are looking for a template or the typical structure for a file (used by the Citra emulator to decrypt 3DS games), it generally follows a specific format where each line contains a "Slot" identifier followed by the 32-character hexadecimal key.
Because aes-keys.txt was distributed as a separate, tiny file, piracy sites would bundle it with thousands of ROMs. Nintendo argued this stripped games of their copy protection entirely, likening it to distributing a master lock key. Citra Aes-keys.txt
Once you have aes-keys.txt , you typically place it in the Citra configuration directory. The exact location can vary depending on the operating system you're using: If you are looking for a template or