I can't get Remote Web Services to publish - I only get the default IIS screen

So, 

I am trying to set up Remote web services for my organization to replace a small business server version - my new server is Windows Server 2019.  

I followed the instructions here:

https://docs.microsoft.com/en-us/windows-server/remote/remote-desktop-services/clients/remote-desktop-web-client-admin

However I am now to a point where I have published IIS to the web and get the default splash page for it, but I cannot for the life of me get it to flip from the default IIS page to the Remote Web Access SSO page.

Any ideas?