[brunis]

If you go to Libreelec Configuration -> System and click Create System and Kodi Backup, you'll be prompted with a dialog for the destination. If you click cancel it will back up anyway.

The cogwheel kinda signals settings, but there are no settings. Something useful like storing on a samba share would be nice, considering how many SD Cards Pi's burn through.

[Klojum]

Something useful like storing on a samba share would be nice, considering how many SD Cards Pi's burn through

I'm not sure how many SD cards you've used so far, but it's not that bad a situation like it was a couple of years ago.
Besides, the new RPi3B+ can boot and run from USB now, that means external USB HDDs/SSDs as well.

The destination prompt is just for that: selecting a destination for your backup, which can be an internal or external location.
Cancelling that backup process there may have a bug, yes...

[Milhouse]

Also, the default backup location is the "Backup" Samba share (ie. \\<your-ip-address>\Backup)- once you have made your backup you can copy it elsewhere using Samba.

[speedwell68]

If you go to Libreelec Configuration -> System and click Create System and Kodi Backup, you'll be prompted with a dialog for the destination. If you click cancel it will back up anyway.

The cogwheel kinda signals settings, but there are no settings. Something useful like storing on a samba share would be nice, considering how many SD Cards Pi's burn through.

 I have 5 PIs of various generations and I haven't had to change an SD card for many years and they are on 24/7.  In the very early days I had a couple fail.