How to show 2D image in User Defined Target in Unity Vuforia

Good Day I have a question about the way how to show simple 2d image on top of detected marker. I have followed some tutorial to show 3d model and it works fine. there is no problem with 3d. The problem starts when I want to add normal 2d object->sprite . When I add simple sprite I can't add texture and when I insert UI image it's added together with canvas and it is not showed when target is detected. The original image on editor is placed then so far that it's difficult to find it. I would be grateful if somebody can highlight me the right direction.