How to move iTunes Backups from one external hard drive to another.

Alright, I need a little point in the right direction.

To save space on my Mac, I had moved my iTunes backups to an external hard drive using the intrusctions on this page:

https://www.imore.com/how-move-your-iphone-or-ipad-backups-external-hard-drive

Now I want to move them to a different external hard drive, but the terminal command doesn't seem to be working, and when I go to backup my iPhone it just keeps going to the Library/Application Support/MobileSync/Backup folder on my Mac.

Not sure what I'm doing wrong. The names of the folders and external hard drive are all correct, the command seems to be going through, but no dice.

Any tips?