I want to create 3d widget in actor, when i hit (LineTraceForObject) i should show widget and if no hit, hide it.
I should create widget - add to viewport or have another way?
You probably want to do a sphere trace so the player does not have to directly hit the object with pinpoint precision but it starts popping up a little but sooner.
Besides that you should only have to add a widget component to the object, make sure it is set to screen and add a widget to it that would be set up to specifically show the interaction key.