iCloud sync allows storing GoodNotes documents in iCloud and keeping them up to date (that is, synchronized or synced) between your iPhones, iPads and Macs. For example, you can start editing a document on one device and resume working on the document on another device.
Even if you have only one device, keeping your documents in iCloud will help in case you need to reinstall the app or reset the device. After a fresh GoodNotes reinstallation, you can simply start the app, enable iCloud sync and have all your documents redownloaded from iCloud.
Since iCloud sync involves data transfer between your devices, please do the following on all of them:
Settings
> iCloud Settings
and enable Use iCloud
.After you turn on "Use iCloud" in GoodNotes iCloud Settings, your GoodNotes documents should be automatically and seamlessly backed up to Apple's iCloud servers. In some cases, however, you might notice your documents aren't syncing properly as they should. Symptoms include error messages about iCloud, inaccessible greyed-out documents, cloud icons with "!" on specific documents.