You can use NameOcean DNS even your domain is on a 3rd party registrar like Godaddy or Namecheap. Follow the steps to use NameOcean DNS.
Update nameservers of your domain
Nameserver 1: ns1.nameocean.net
Nameserver 2: ns2.nameocean.net
Nameserver 3: ns3.nameocean.net
Nameserver 4: ns4.nameocean.net
2. Create a DNS Zone
Login your NameOcean account. Go to DNS section of NameOcean Dashboard.
3. Write Your Domain Name and Click the button "+ Create New DNS Zone"
Write only hostname of your domain, for example "nameocean.net" or "example.com" do not add subdomains.
You can start managing your DNS Zone. For example, you can start by adding A (address) Record to point your domain names to IP Addresses. For detailed instructions to manage DNS Zone go to How to manage DNS Zone.