It’s required that you have installed CentOS WebPanel and at least one public IP address.
** Please note that some domain providers will require that you have two different IP’s.

Settings
CWP.admin – DNS Functions –> Edit NameServers IPs

Add here add your subdomains you want to use for the NameServers and one IP for each nameserver eg.
ns1.centos-webpanel.com --> 185.4.149.83
ns1.centos-webpanel.com --> 185.4.149.90

If you are using one IP then it should looks like:
ns1.demo.com --> 185.4.149.83
ns1.demo.com --> 185.4.149.83

Don’t forget that this NameServer must be registered with your domain registrar or they will not work!!!


How to Register your Nameservers with Domain Registrars

Enom Instructions: http://www.enom.com/help/faq_dns.asp
Godaddy Instructions: https://uk.godaddy.com/help/add-my-own-host-names-as-nameservers-12320
NameCheap: https://www.namecheap.com/support/knowledgebase/article.aspx/768/10/how-do-i-register-personal-nameservers-for-my-domain