I have posted this problem as an bug Issue #822 in the Jupyter Book repository. Our chapter numbers are not rendering when we build the book.
In an earlier version of jupyter-book the local build of the book accessed by opening the file ./_build/html/index.html in a Google Chrome browser, the left-side navbar looks as expected. I've circled in red the navbar chapter numbers we expected.

However, with the updated jupyter-book=0.7.3 and the updated _config.yml and _toc.yml, the book now renders locally and on the GitHub page upon build with no chapter numbers.

I have posted this problem as an bug Issue #822 in the Jupyter Book repository. Our chapter numbers are not rendering when we build the book.
In an earlier version of
jupyter-bookthe local build of the book accessed by opening the file./_build/html/index.htmlin a Google Chrome browser, the left-side navbar looks as expected. I've circled in red the navbar chapter numbers we expected.However, with the updated
jupyter-book=0.7.3and the updated_config.ymland_toc.yml, the book now renders locally and on the GitHub page upon build with no chapter numbers.