Configure front matter for jupytext percent notebooks

[Bain-OS]

Hey all,

Not sure if this is the right place to ask, so please forgive me if not.

I am using jupytext, myst_nb and sphinx.

I have a line in my conf.py that looks like this

nb_custom_formats = {
    ".py": ["jupytext.reads", {"fmt": "py:percent"}],
}

I want to hide my code cells for a particular notebook, I've tried a couple variations that looks like this in my code, but these lines end up being rendered into the page and the code source is still there.

#%% [markdown]
"""
---
mystnb:
  remove_code_source: true
---
"""

Does anyone know how to achieve this?