Hi everyone! So I’ve faced a problem: I need to connect “Hit Actor“ output which has Actor Object reference to target input of that “Interact“ node, but it has some kind of “BPI Int Interface“ input. How can I change target interface so I could connect the needed parts of nodes?
cast to BPI Int 
Welcome to Unreal Forums,
You probably have the same interface implemented inside your BP_FirstPersonCharacter and you’re calling it inside the BP_FirstPersonCharacter instead on the HitActor. The target pin color is a giveaway.
To call interface on another actor you need to pull of hit actor and then find your interface function name (Interact). It should say something like Interact (Message) and the node will have an envelope icon in top right corner.
Screenshot for clarity. Ignore extra input pins I have on my Interface function.
