Backup Synology NAS via 10GB Ethernet Network to External Drives attached to Mac Mini M4

I am a newbie to Synology NAS, and set up a 923+ for my personal photography image storage. The NAS is connected to my Mac Mini via a 10GB switch. My router is connected to the switch via a 2.5GB Ethernet connection. I am storing all my image files and related Lightroom backups on the NAS, and it works perfectly. I would like to backup the NAS to a couple of external drives directly connected to the Mac. This would allow me to use my existing Backblaze home plan to back the externals up to the cloud.

I would greatly appreciate suggestions on the most efficient way to achieve the above. I know that I could use Backblaze’s business app directly from the NAS, however the storage cost would be orders of magnitude more expensive than using my personal home Backblaze plan. I’m not running a business – just trying to achieve an efficient, cost-effective and safe home network and backup solution for my photography.

Thanks!!!

What you can do is go get https://www.goodsync.com/
Use the 20$/ year plan. What you can do than is backup your NAS folders to a external drive. This drive will be backed up to Backblaze.
Thats what i do for over a year and it works flawless.

you could use syncthing, if you have homebrew installed: brew install syncthing