TrueNAS Core remotely shuts down a TrueNAS Scale system - how?

[Whitesnake]

I have my main TrueNAS Core system, which is running 24-7. I do backups for a second TrueNAS Scale system. Therefore I do a wol command, run rsync jobs and afterwards I do a cronjob on the Scale system to shut it down. Problem: the cronjob works manually, but not as a cronjob. I have searched the forum, but there is no solution.

So I thought about a workaround: is it possible to ssh from the TrueNAS Core system to the TrueNAS Scale system as a root and run a command and this as a cronjob? If I ssh from my workstation to the Scale Server and run the command it works. Since I need to do this from a 24-7 system (my workstation isn't running 24-7) my only choice is the TrueNAS Core system.

Thanks for your help.