How can I check if an item has inventory?

I made a custom item that allows player to duplicate any item with a certain cost. However, I do not want it to be able to duplicate items with inventory(to be precise, I don't want to duplicate items inside the item's inventory).

How can I check if an item has inventory? Or, instead, how can I clear an item's inventory?

I am even thinking about setting empty itemstack in all slots of the item's inventory manually...

How it currently works is when the item duper is in off-hand and target item is in main-hand and player right-clicks, the player receives one same item as the one in main-hand and lose one item duper.

Using MCreator 2024.1 for Minecraft 1.20.1.