How do I call the variable class FOnButtonClickedEvent in a widget UI C++ class?

In the docs, it says that the event for a button widget being clicked is FOnButtonClickedEvent. But it’s a variable, so I was wondering how it could be turned into a function so that when the player clicks on it it executes something. I assume it needs to be used in conjunction with the SlateHandleClicked() function, but I’m not sure about the syntax. In BP, when you add an event for button clicked, it would add an event in the event graph that you could hook up functionality. What’s the C++ equivalent to this in a widget UI class?