Inventory refresh

Hello, i wach tutorial and i make inventory system. Now when i collect items their number is showed in widget. In it i have buton “drop” and when i remove any item it is showed only if i close and open the widget. How to make my widget to refresh when i click any buton?
If you want i will show photos on widge- event graph

JUST DO IT

here is a song that helped me and it will help you: