The CanCurrentlyInteract function does not need an input pin. You can remove that (click the X next to the sorting buttons for CanCurrentlyInteract? boolean to remove). You don’t need an input because the purpose of this function is to find out if the actor can interact. The Actor doesn’t need you to tell it anything when you call the function; it is only telling YOU something (in the output pin).
So when you set up the function implementation in the Actor’s class (not the interface) then the function definition of the interface will be used, which only needs the output pin for the return node.
In your Actor’s implementation of that interface’s function all you must do is return the value of that actor’s CanCurrentlyInteract boolean variable, into the return node.
In this way, your Actor returns the information to whatever called the CanCurrentlyInteract function that the Actor has because of its Interface. The information returned is simply the contents of that Actor’s CanCurrentlyInteract variable, which is true or false.
So now all your Interactable actors not only have an Interact function, but also a function which tells the thing that called the function whether it is able to interact at that moment.
so if your Player Pawn calls CanCurrentlyInteract, then the actor it is called on should Return that boolean variable, which will be true if the actor is not moving, and false if it is moving, because we programmed it to set its variable that way. All the player pawn has to do is check what the CanCurrentlyInteract function returns for the actor you’re aiming at, before deciding whether to interact or not.