Embed HTML subproject into existing Sphinx documentation

[HealthyPear]

I am working on a project which has its own sphinx documentation (based on the pydata-sphinx-theme) and part of this project supports Jupyter Book to show off a set of notebooks.

I would like to show the jupyter book as part of my Sphinx documentation.

There are different ways I explored on how to do this, but non seem to work well.

What I end up is my HTML docs and a subfolder with separate HTML docs from the book.

Is it possible to add the index page of the book subproject as a page of my main sphinx documentation?