This is the best of the four TOC plugins I've installed and tested today, as it generates a TOC within the page, is closely configurable, and produces nested TOCs. It behaves slightly strangely, in that some of the TOC entries (eg "1. introduction") have the whole entry hyperlinked to internal anchors, whereas some others have just the TOC entry prefix (eg "1. ") hyperlinked. However, that might be to do with the text (written in Libre Office) which I copied into the Visual view.
All in all, very useful, and thanks to the author.