1. Make sure you have added domain like tutorial in this link Add DOmain.
2. Login to http://freedns.centos-webpanel.com
3. Click "List Zones" and choose your domain.
4. Next, create A record as your subdomain. Example, if the subdomain is samplexxx.domain.com,then fill Host With samplexxx, type with A, and Destination with IP of your hosting server. Then click "save".
Please looking screenshot bellow.
