Unable to open STL File properly

The file in question seems to be:

https://www.etsy.com/listing/1251045211/sea-turtle-stl-stl-pack-for-3d-printers

The files open as expected in an STL program:

It may be imported into Carbide Create Pro as previously described:

https://my.carbide3d.com/gswccpro/07/

and also see

and

note that only binary format STL files may be imported: Importing ASCII format STL files

Set up the file and import the STL:

Since the orientation of the STL doesn’t match what we want, we adjust the options as necessary:

setting 3D Orientation to “Front”

Since we only need the auto-tracing, we can quit at this point, delete the 3D model, and use the auto-traced geometry:

Offset to the outside by endmill diameter plus 10% or so:

Deselect what we want to keep:

and delete:

so we can then select everything and do an Advanced V carving for the best possible detail:

and then add an Outside Contour to cut things out: