It's recommended to regularly backup the song library.
  • iOS, Android
  • Android emulator
  • Amazon Fire

 

iOS, Android

In iReal Pro, tap on Settings -> scroll down to Backup and email the Backup.html file to yourself or store it in Dropbox, Google Drive, Files (Apple) or similar cloud services.
 
 
(Older versions of iReal Pro iOS and Android, More screen -> Backup)
 

Android emulator

 

Amazon Fire