brand new user to Pro Sites and I just downloaded

Hi, brand new user to Pro Sites and I just downloaded and Installed Pro Sites. I would like to get domain mapping set up on my multisite, but, it does not appear to be working. I did look, and saw that WPMUDEV does make a plugin, but It said I had to upgrade my account, which was close to $100 to upgrade. Certainly this does not seem right. I would love to get this up and working on my site without spending an arm and a leg. Thank you.