Why and how to fix this?
This happens because you are missing an index.html on the directory you are accessing.
If this happens on your home page, which means you are missing an index.html on your Publish directory.
If this happens on the subdirectory of your site, for example,
/blog, this means your site doesn’t include an index.html on that subdirectory e.g.,
Custom 404 Pages
If you want to create a custom 404 page for your site, just create an index.html file and put it under