Error while using .stp/.step files

I tried to use a .stp/.step file. The upload of the file and the creation of the shortcode works but when I access then the page the viewer returns the following error:

Failed to import model. (Failed to load occt-import-js.)

The console shows that the viewer is not able to find that file “occt-import-js-worker.js”

Somehow for example .stl .glb is working fine.

The page I need help with: [log in to see the link]