@AllMediaLab to make files without extension editable in PG, add NOEXT to the list of editable files:
Static website hosting such as Netlify (we use them for our main site) usually strip out .html extensions from pages.
Re FTP access, I strongly feel that it is a dangerous way of uploading files to the server. So easy to make a mistake, especially if clients are doing it. It is better to setup some kind of GIT-backed flow and setup an icon on the desktop that will push changes. In case of problems it is easy to restore files.