3D Objects from Illustrator - Looks like you *cannot* edit them in 3D Stager

I've figured out how to import an .obj file from Illustrator into 3D Stager,

however, once the very simple obect is inside 3D Stager, I cannot edit any part of the oject.

All I wanted to do is extrude the object a little bit less, but there are NO options to do so.

Any help is appreciated, thank you !

( Am I exporting the 3D object from Illustrator incorrectly ? ) ( by the way, I extruded the shape in Illustrator

using the new 3D panel and then chose to export it as an .obj )