I take it back, if you just use Sigil, it creates the ncx files, but not an actual ToC (why it can't use the ncx files as the Table of Contents is beyond me...)
edit:
But you can generate a table of contents using this script from a thread here
https://www.mobileread.com/forums/sho...d.php?t=121607
And KindleGen will make a Kindle friendly TOC if you include it.