Create Texture Share Device node with the same viewport handle as the thrower's. All the projector's nDisplay handles are listed as suggestions so you can simply click on one of them.
If everything is set up correctly, you'll see Unreal's texture in the properties of Texture Share node once you click on Listen checkbox.
Use the texture
You can use standard workflow to get the Unreal texture to a thrower. The path usually leads through a Render to Canvas node, however, you can also use Set Texture node to apply it to the thrower directly.