[SOLVED] 'Atahualpa Page Options' not appearing in page edit panel settings

I apologize in advance if this thread ends up in the wrong forum. Couldn't find where else to put it.

I think the title says it all.
The settings panel under page editing mode offers me to turn on or turn off a number of toggleable panels, such as Yoast SEO, Version, Discussion, Comments, Permalinks etc. Normally I would also find the Atahualpa page options here. But it is alas not.

Where do I find the way to include this checkbox?

Best regards and all that jazz