Have you followed these steps below?
Log in to your website: http://authors.tertulia.com/login — you’ll get an immediate Magic Link sent to your email.
Go to the Settings section in the navigation menu and select Domains. Just choose the option that says "I already have a domain", then enter your domain name. From there, we’ll guide you step-by-step through connecting it and you can follow the instructions below as well.
If so, sometimes it takes 1-2 hours for the DNS changes to fully propagate and connect your domain to your Tertulia site.
If the allotted time has passed, however, and all of the above steps were completed, please reach out to authors@tertulia.com so we can provide assistance.