You buy “Dragon Quest Builders 2 – Aquarium World DLC.” After installing the main game, you enter the 20‑digit serial key from your receipt. The game connects to the server, confirms the key, and instantly unlocks the new aquarium‑building world in the main menu.
If you have purchased a license legitimately, you want to ensure the installation process goes smoothly. Here is how to manage your "keys to the world": serial key unlock the world install