On the old device, I’d make a backup. You'll find backup in the iRp app settings.
Songs / Playlists / More
Then using wifi, I’d send it to my DropBox account. That way it wouldn’t get *lost*.
I use Dropbox but there's also iCloud, Google Drive and others too…
(It's a good practice to regularly archive a backup of your songs and playlists)
Using my current device, I’d sign into my Dropbox account and download the backup I just made from my old device to iReal pro.