To register your personal Nameservers for your domain as a reseller, simply follow the below guide
1. Login to your Client area
2. Navigate to the Domains Big Menu
3. Click on the Primary domain you wish to create Personal Nameservers for
4. Enter your preferred Nameservers and other associated IP address.
6. Click Here to learn how to set up personal nameservers and make them active on the side of your WHM panel.
You are done.