You can’t put a 3D model “on” a widget. A widget is 2D. You have a 3D environment, when you “add” a widget to the viewport, this is just a 2D “picture” that sits in front of the camera, it is not actually in the world. So if you want it to “appear” as if the character is in a certain spot on the widget you have to create your widget with a blank space where you want the character to be located and “design” the widget menu around that blank area.