Move iphone backup to different computer

I just got a new MacBook Pro and I would like to move an old iPhone backup from my iMac to the MacBook. This seems easy enough to do when I look up how to do it. It says to find the backups in Macintosh HD/Library/Application Support/MobileSync/Backup.

The problem is, I can't find the MobileSync folder. It just doesn't exist on either computer. Can anyone help? I really just need to move a backup.