Does the backup app work properly now? I tested it ~ 6 month ago and nothing worked.
What backup app?
I think you must test it on your own.
I think the better way for backup/restore is Backup and Restore. Moreover, it can be very individual due to its own installation.
More important than a backup, however, is to restore the backup from time to time on a test system. This applies to both the app you cited and the instructions I provided.
Maybe you want to try the Backup/Restore-scripts from @DecaTec at DecaTec/Nextcloud-Backup-Restore: Bash scripts for backup/restore of Nextcloud - Nextcloud-Backup-Restore - Codeberg.org?
I used the scripts to completely backup an instance and restore it on a new VPS once - maybe this is the backup solution you may be searching for?
Best regards,
Oliver
Does the Decatec solutions work to safe backups on FTP or something else?
any infos about that?