Preview widgets in blueprint

Hello
Before reading this, please understand that I’m fairly new to UE and I’m still learning, in case I may ■■■■ someone by my question.
I’m currently trying to make a custom grid inventory system for my game.
For now I only have the UI element for the inventory.
I’m creating the widget using c++, I’m not building it by hand using blueprints because I want to reuse this inventory widget more then once (and I like c++ more).


(This is how it looks for now on Play)
I was wondering if I could preview the inventory also in the blueprint editor. When I press simulate the cells for the inventory are not added in the GridPanel component. Is there a way I could preview it in the editor?

(Here, I’d like to see the cells like in the first picture)
Thank you for any help <3