Nallath,
Thank you for help!
Not sure how I missed that in the list of extensions. It worked perfectly.
TIP: For all using Windows, install the PowerToys v0.64 found here:
https://learn.microsoft.com/en-us/windows/powertoys/install
The power toys has a windows explorer (File Manager) previewer for GCODE, STL and a few other types.
For gcode you have to have a thumbnail in the code. Hence my initial question.
Thanks to Nallath, I can now see the preview in windows as well as the 3D printers display!
Thanks again,
AF