Notebooks has not been supporting iCloud or iCloud Drive for a couple of technical issues, but we have good news: right now (early 2021) we are integrating Notebooks with iCloud, and things are looking very promising. So if all goes well, the next update will allow you to save and sync your documents though iCloud, and this seems like the most natural and seamless sync option available for Notebooks on iOS and macOS. You can be looking forward to it!

Why doesn’t Notebooks Sync with iCloud?