Creating a custom domain can be a little tricky depending on your provider, we have added some guides here for some of the more common domain hosts, but the basics are this.
Go to your domain name provider.
Click in your DNS settings
Create a CNAME record, use the @ symbol for the HOSTS and then add whitelabel.adsoup.io as the URL.
Then redirect www.yourdomain.com to yourdomain.com.