I've created a room where I trade the code for the card dragon.
It's an open chat room on KakaoTalk.
You can participate [anonymously], so please feel free to come in and ask.
There is a transaction description inside the room, but we also receive questions before entering

[English room] Dragon Village Collection Trad
https://open.kakao.com/o/gbNzkyNf

[Japanese room] ドラゴンビレッジコレクション取引
https://open.kakao.com/o/g5cPbyNf