Truenas backup over internet to a remote Qnap - how?

Hi everyone.
Having a small setup with a truenas of 140TB that I have been backed up to Dropbox when their premium tier was unlimited space. That has gone away, so I want to have an offsite backup instead of dropbox/cloud. I have an old qnap NAS that I can fit 140 TB onto as well, and I will put it in my home.

The question is; what is the easiest and safest way to have the Truenas do nightly backups to a remote Qnap NAS?

Running Scale 25.03 and the latest Qnap OS