I'm trying to run the code for the geoviewer examples on geo-three.js, this one: https://github.com/w3reality/three-geo/tree/master/examples/geo-viewer
When I try to build the app, as the readme.md indicates, I get this error:

If I execute the second command it doesn't work, because of the said previous error. And even if I try to load the index.html in the browser all I get is a blank screen:
What am I missing? Because all the relative paths for the includes are right...