if you backup locally so not over a network share you could use Backblazes Personal Backup ( hub.docker.com/r/…/backblaze-personal-wine ) it’s like 8$ for unlimited backup
but they have some kind of tracking for blocking cifs/smb shares but you can circumvent that using dolanymy current setup as my data is mainly just a Hetzner 20tb storage box I have a second windows VPS that mounts that CIFS storage using dokany und Just run backblaze Personal backup there was a real hassle to set up an the backup takes for ever but yeah it works