Potion Crafting system (Third Person)

I wish to create a potion crafting system.
I had the idea to have a cauldron have its own inventory. The (third person) player adds objects to that inventory by dropping objects into the pot (hitting the collider)
The crafting system uses that inventory to create potions.
The only issue is that I’m very stuck with getting the cauldron to work with an inventory. I already made a UI but I don’t get how to make the cauldron register when the object hits the collider and to add that object to the UI
Any tips? Or help? I …