Hello Frank, can you check that Jupytext’s content manager is active? If your configuration is correct, you should see Python scripts and markdown files displayed with a notebook icon in either Jupyter Notebook or Jupyter Lab.

If you don’t get the notebook icon, then

• double check Jupyter’s config
• and restart Jupyter Notebook or Lab.

You are also welcome to test Jupytext on Binder.

By the way, on November 14 I will present Jupytext at PyParis. You may be interested in the demo script which is already available.