Obsidian + Nextcloud + Pythonista = ?possible

I have my Obsidian vault in Nextcloud, which I use to keep it synced across devices. I would like to use Pythonista to read and update a file in my vault to automatically create reminders in iOS, but I’m having a problem with file access. I seem to be able to pull a copy? of a file out of Nextcloud and into pythonista, but if I try to “add” a folder so that I can read from and write to it in place, Nextcloud is greyed out. Same situation if I try to “bookmark” a folder with Taio. Anyone understand what’s happening here and maybe know of a work-around?