If your book features Chapter Titles and you’d like to remove the automated numbering from the TOC, here’s how to do that:
Click the three dots beside the title Body in the left navigation panel
Uncheck Numbered
This will also remove the automated numbering from your individual chapter headers, so you’ll want to make sure you’re not relying on those as your chapter titles.
If you'd like to remove the automated numbering from an individual page or chapter:
Hover over the page title in the left navigation panel
Click the three dots that appear
Uncheck Numbered