Hello! I am trying this feature for the first time. However, I'm unable to add my own items to it. When I press the + button it only adds the potato mascot of the software that comes in default. There's no window opening to where I could select my own items. Am I missing something? Please help. Thank you!

oh hey i'm not the dev, but to add your own item click the little potato mascot that's in the little box in the top and you will be able to upload images and attach them by right clicking when you're holding left click over the thing you wanna attach it to even eyes ^^