That’s the paid one, correct? Unless you post the code (which you can’t do as this is a paid addon) or someone else has experience with it, I can’t help you out. My guess, as this is how most addons from SF come, is to put the folder with the addon name and sub-directories(lua, materials, sound, etc.) into your addons folder. There may be config too, but I can’t tell you for sure without access to the files. However, If you actually bought the advanced inventory addon off of Scriptfodder, then you can ask the developer of the addon for support. From looking at the addon page, there is a readme.txt file included with it that should explain it. If you got it off of LeakForums, then good luck getting it to work correctly.