iCloud Archiving and Restoring
When Playlists and Custom Versions are created/modified Appcompanist attempts to save them in your iCloud Drive if you have iCloud Drive and the associated Appcompanist setting enabled. These can be found in the Settings app on your device. Appcompanist has the iCloud archiving setting enabled by default, and iCloud when enabled usually has iCloud Drive enabled by default as well. Appcompanist will alert you if you try to restore your data and these settings are not enabled.
To restore saved playlists and custom versions after a new install or after deleting Appcompanist, go to the Info/Help tab and select "Restoring data from iCloud." This will start a restore process in the background and you will get a notification when it's complete. (If you have disabled receiving notifications from Appcompanist then you will not see the notification.)
Note that this is not a substitute for regularly backing up your device, as that is the most secure way of ensuring you don't lose any data. There are some errors that can occur with iCloud that are difficult to detect and/or recover from, so restoring from within the app should be considered a convenient way to backup and restore playlists and custom versions, and hopefully you won't need to restore your phone completely to recover your playlists and custom versions.
This can also be an easy way to move playlists and custom versions from one device to another (if they are using the same Apple ID account and have Appcompanist installed.) However be aware that the restore will not overwrite local copies of playlists or custom versions, only add those that don't already exist on the device.
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