Backup USB Drive(s) on a MyCloudEX2Ultra over the network to a WDMyCloud-EX4100

I have 2x usb data drives connected to an MyCloudEX2Ultra DATA NAS that need to be setup to be backed-up to the new WDMyCloud-EX4100 Backup NAS sub folders D1, D2.
I have the MyCloudEX2Ultra DATA NAS already setup to auto backup to the new WDMyCloud-EX4100 Backup NAS.
when i went to the setup USB drive backup GUI I was surprised I can’t select a network location as an destination, grrrrr.

so i think i need to use rsync/ssh to do this?
the goal will be to automate this to run a daily backup of those drives.

These are some of the pages i have read through already.

[Backing up select shares]

and

[Success #3 rsync backup between My Cloud devices]

and

[Backing up between two My Passport Wireless devices]

and

[[HOWTO] Securing SSH with private encryption key and passphrasec for remote connection]

and
https://linuxhint.com/copy_ssh_keys/

I can’t get “mount -t cifs -o” to work.
nor can I get the ssh keys working for sshd/root?
i was using the ssh key info from the Kayvan post before i got lost.

i think if that works i can run….

mkdir /mnt/Seagate4TBLG
# $??? (What CMD to mount?)
rsync -az /shares/Seagate4TBLG /mnt/Seagate4TBLG #>192.168.102.174/shares/SystemBackups/Seagate4TBLG/
umount /mnt/Seagate4TBLG

mkdir /mnt/Seagate4TBmini
# $??? (What CMD to mount?)
rsync -az /shares/Seagate4TBmini /mnt/Seagate4TBmini #>192.168.102.174/shares/SystemBackups/Seagate4TBmini/
umount /mnt/Seagate4TBmini

or use the script by Kayvan Sylvan.
Thoughts?

I’m trying to set this up for somebody to be fairly automated.
I’m somewhat familiar with linux but when the commands don’t work as intended It gets really frustrating.
Something probably ended up in the wrong folder, or with the wrong permissions.