Backup! Various methods

Please do backups regularly. Here are various ways to backup from easiest to hardest.

If you have a newer iPad, it is also possible to Airdrop all of your files to a computer. Go to Settings->Utilities and choose Airdrop Documents to Computer. This will use Airdrop to send the entire Documents folder to a computer. This will be a complete backup of unrealBook files.

Use Airdrop Documents to Computer to make a complete backup of your files if you have an iPad Pro

You can use Catalina/Monterey/Ventura and later MacOS to create a backup. SEE THIS PAGE.

Another way is to use iFunBox.

Here is how to backup and copy to another iPad with iFunBox

Here is how to backup and copy to another iPad with iMazing which is an amazing paid program.

(old and outdated) Before Catalina, the fastest and most reliable way is to use iTunes.
This method will backup only the unrealBook music files and works well.

The following methods require you to restore the entire iPad if you need to recover the backup:
Make a complete backup of your iPad via iTunes.

iCloud backup is another method but it requires you to recover the entire iPad.
How to use iCloud backup: