When you install the 3D Shapes extension, it adds a “3D Shapes” sub-menu to the “Draw” menu.
NOTE! The menu image on it’s Extension Warehouse page, is obsolete. That image is from pre-v2014. (In SU v2014+ the 2D Shape commands were moved to a “Shapes” sub-menu.)
Sorry. The list item “su_shapes” is actually the “su_shapes.rb” extension registrar script for the 3D Shapes" extension. This script actually creates the real checkable list item that has the label “Shapes Tool”.
If you cannot “check” it (so it loads the it’s extension,) then you have your “Extension Load Policy” set to “Identified Extensions Only”.
And weirdly, yes, this Trimble extension has not yet had a ID hash created for it ! (Did not realize this as I run with an “Unrestricted” extension load policy (because of testing, and programming.)
You can switch to “Approval” mode, and approve it manually.