Questions about Mu Domain Mapping on Multisite

What I would like top do is use my wordpress multisite installation to allow me to easily create a bunch of basic websites for clients. Each of these will need to be an individual wordpress site with it’s own domain that I would map to it.

I setup my wordpress site as a network and followed all of the instructions on how to do this properly. I then installed mu domain mapping and followed the instructions for that as well.

When I create a new site in my network dashboard, I get this error message:

The server at gustafsontrading.gustechreviews.com can’t be found, because the DNS lookup failed. DNS is the network service that translates a website’s name to its Internet address. This error is most often caused by having no connection to the Internet or a misconfigured network. It can also be caused by an unresponsive DNS server or a firewall preventing Google Chrome from accessing the network.

Here is a screenshot of how I setup the domain name when I created it: https://imgur.com/aUqYlcd

This one has a subdomain mostly because I am testing things out, but in the future I would like to use the clients domain name.

Have I done something wrong? Have I neglected to do something? I am kind of new to this so any help is appreciated.