You should be familiar with the Modding Basic Concepts tutorial before following this one.
In this tutorial, I'm going to show you how to add a new icon for a custom ability or item in Pillars of Eternity II: Deadfire. You must have Deadfire version 2.0.0 or later to use this functionality.
I've already created game data objects for two custom items, and I've created two PNG icons for each: a small 42x42 icon, which will be used to show the item in an inventory slot, and a large