Why not simply use the Calibre-web Windows installer? See
Calibre-web V0.6.19 Daria for the download link. I would assume that you went to that site to download the bits and bobs for the Linux install and didn't click on
Releases or
V0.6.19 Daria
As mentioned in the web page you linked to:
For more information go to
https://github.com/janeczku/calibre-web.