Backup and Restore functions are greatly simplified on Version 2 of the App. Backup can be performed with just a few taps of the screen, so please backup often in case your device becomes lost or damaged.
Backup
This function is now quite easy. Click on Help & Backup and then on Backup, and the app prepares a zip file which contains all the card images, notes, and readings. A screen appears, similar to what you see when you share a photo, giving the many choices for sharing the file, including AirDrop, Messages, email, and Save to Files.
A recommended procedure is to choose Save to Files, which will store the backup in a place where it can be readily Restored. Be sure to change the name of the backup file to include the date of the backup. Best practice is to create a folder within iCloud Drive Location of the Files App and then store all the backups there. This will provide another level of backup outside of your device and also make your saved backups accessible from other mobile devices, if you have any.
Visit Apple support documentation for more information on how to use the Files app: Access and manage your files in iCloud Drive – Apple Support
To save directly to another device, you can choose email, text messaging, or you can AirDrop to another iOS device or to a Mac.
Restore
This function is quite easy and no longer requires connecting to a Mac or PC. The App expects to find the Backup file in the Files folder of the device. If your desired Backup file is already in the Files folder, just click Help & Backup and then on Restore, then navigate to the appropriate Files folder and highlight the zipped file which you want to restore. (You no longer need to unzip the file before restoring). Answer “Yes, Restore” and the backup data will be restored to the device.