Can't access an event inside an widget that holds 2 inventories.

I can’t access an event within a widget that is used to clear the childrens and redo the inventories of just 1 of the inventories. If I use print string, the name of the item within that window is printed, so why can’t I Could you access and update it?
In this case, the BACKPACK slots:

I can’t select the BACKPACK wrap box and select the icons, if i print string, the icons let the print string print their names or any other thing like condition, weight. I can’t only access, clear and rebuild for selection purposes.