Audio
The Ultimate Inventory System shares the Audio System with the Ultimate Character Controller.
Please find the doucmentation for the Audio here
Specific to the Inventory system, you will find a simple yet very useful component.
Button Audio Handler
Add this component on the same gameobject as your Button, ActionButton (or ItemViewSlot) to play sounds.
Button Audio
It takes in a ButtonAudio object. To create one do right-click in the project window:
Create/Ultimate Inventory System/UI/Button Audio.
For AudioConfigs, refer to the rest of the doucmentation for the Audio here