Modding Help Defining contents of storage items in custom dungeons?

I've just got started with Tiled and I know how to place stuff down be it blocks or objects. But how do I decide what items appear in the many storage containers I've placed on my custom map? It would be great to know.

 

Here is a very good guide on making dungeons, it will answer that question and more. https://steamcommunity.com/sharedfiles/filedetails/?id=1660027998

 

Thank you. Now I just have to master the art of *.treasurepools files.