Code

Editor

[DISCLAIMER]
This page assumes you've correctly setup Unity and followed the steps within the first two pages https://thunderstore.io/c/lethal-company/p/TeamXiaolan/DawnLib/wiki/4097-a-unity-setup/
https://thunderstore.io/c/lethal-company/p/TeamXiaolan/DawnLib/wiki/4099-b2-registering-via-unity-editor/
If you have not finished those steps, finish them and come back to this page.

Make a folder for your achievement and inside it add a Registry folder.
In the registry folder right click, hover over create -> DawnLib -> Definitions -> DuskAchievementDefinition.
Put the DuskAchievementDefinition and all related assets under an AssetBundle like "ultimateachievementassets".
Include this AssetBundle into the list of AssetBundles in your ContentContainer (made during the Unity Setup page).

Done!

[Remember]
You may always contact @xuxiaolan on discord, whether through the lethal modding discord or DMs for more inquires or any difficulties encountered.