How do you retrieve deleted file in notability?

To retrieve a deleted file in Notability, first check the "Recently Deleted" section within the app, where files are stored temporarily before permanent deletion. If the file is found there, you can restore it back to your library. If it's not in "Recently Deleted," you may need to rely on a backup from iCloud or another cloud service if you had syncing enabled. Always ensure to back up important notes to avoid future loss.