Open Excel, and you will see a new tab in the ribbon at the top that says PyXLL.

Google is partnering with authors, researchers, and publications to launch “featured” notebooks within its AI notetaking app, ...

Then, restart your Jupyter Lab server, and make sure Jupytext is activated in Jupyter: .py and .md files have a Notebook icon, and you can open them as Notebooks with a right click in Jupyter Lab.