UrBackup 2.5.26 on trueNAS via docker

I using urbackup many years, but new installation I made on trueNAS scale (debian inside) and docker app.

I have some issues:

root@urbackup-ix-chart-6ddb5cdd5c-4r4vx:/# urbackupsrv remove-unknown -u root
2022-10-06 19:19:33: Going to remove all unknown files and directories in the urbackup storage directory. Waiting 20 seconds…
2022-10-06 19:19:53: Shutting down all database instances…
2022-10-06 19:19:53: Opening urbackup server database…
2022-10-06 19:19:53: SQLite: recovered 3292 frames from WAL file /var/urbackup/backup_server_link_journal.db-wal code: 283
2022-10-06 19:19:54: SQLite: recovered 100408 frames from WAL file /var/urbackup/backup_server_links.db-wal code: 283
2022-10-06 19:19:54: Testing if backup destination can handle subvolumes and snapshots…
Testing for btrfs…
ERROR: not a btrfs filesystem: /backups/testA54hj5luZtlorr494
TEST FAILED: Creating test btrfs subvolume failed
Testing for zfs…
TEST FAILED: Dataset is not set via /etc/urbackup/dataset
2022-10-06 19:19:54: Backup destination cannot handle subvolumes and snapshots. Snapshots disabled.
2022-10-06 19:19:54: ERROR: Error getting free space
2022-10-06 19:19:54: ERROR: Error cleaning up.

My backup pool is located on volume zfs, (sportowa/urbackup) but if I set this in /etc/urbackup/dataset is the same:

Testing for zfs…
TEST FAILED: Creating test zfs volume “sportowa/urbackup/testA54hj5luZtlorr494” failed
2022-10-06 19:21:59: Backup destination cannot handle subvolumes and snapshots. Snapshots disabled.
2022-10-06 19:21:59: ERROR: Error getting free space
2022-10-06 19:21:59: ERROR: Error cleaning up.
root@urbackup-ix-chart-6ddb5cdd5c-4r4vx:/#