Accessing button from TriggerBox

Excuse me if this is in the wrong forum.
I’m new to UE5 and I’m trying to change the state of a button, in my main menu after a triggerbox has been triggered.

I have managed to change the state of a button in my menu using another button in the same menu, but when I try the same approach from my TriggerBox, then the property cannot be found!

  • where is the script we see above? An actor in the level?
  • how and where do you create the main menu?

The script above is located in Game/ and the ui in Game/UI.
In the UI tab i have a widget blueprint for the main menu!

No, these are just folders. I meant the script, actors, object, widgets. How do you out them into the game?