If you not have backup your playlist, you can reference How to back up music.
Open Kaku and checkout to
Setting -> Backup -> Sync data from Local / Dropbox,
and choose your previous backup method.
Sync data from Local.
Kaku will have notification, if you don't want to replace your playlist click
Chancel otherwise click
Choose your save path and import it.
Sync data from Dropbox and you can see Dropbox API Request Authorization.
Don't Worry！we will not save your any information.
You can see authorization request, click permission and will sync your playlist.