MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
That's not how it works. Designs have to be made with OpenSCAD and be made parametric. In that case the Customizer button should be on the page of that specific design, in the right column next to the picture.