CWP DNS Part 1 : How to Configure DNS properly for CentOS WebPanel on CentOS 7.6

After hosting my parent domain on CWP7.admin, I am getting dns error and i'm not able access my server using my server FQDN but i can access using my server IP.
So what can i do for that problem ?

Yes, you have to fix the error .

Environment Details:
Distro Name: CentOS Linux release 7.6.1810 (Core)
CentOS-Web Panel version: CWP7.admin
CWP version: 0.9.8.757
WebServer: Apache Only
FQDN: host.datahead.biz
IP: 192.120.10.3

1.Change Hostname Permanently:

# hostnamectl set-hostname host.datahead.biz
# hostnamectl
   Static hostname: host.datahead.biz
         Icon name: computer-vm
           Chassis: vm
        Machine ID: 7400071490ea4f7d931374824ad4b52c
           Boot ID: 6e1f2d76495d4b318c25c4a1195aa130
    Virtualization: vmware
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
            Kernel: Linux 3.10.0-862.14.4.el7.x86_64
      Architecture: x86-64 

It also writes this information to the /etc/hostname file as well.

# cat /etc/hostname
host.datahead.biz

2.One thing the hostnamectl command doesn’t do is modify the /etc/hosts file, so we’ll still need to do that

# vi /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.120.10.3    host.datahead.biz     host
127.0.0.1       host.datahead.biz
172.0.0.1       autoreply.host.datahead.biz
:x  (save & quit)

# vi   /etc/sysconfig/network
# Created by anaconda  
HOSTNAME=host.datahead.biz
:x  (save & quit) 

# vi  /etc/resolve.conf
# Generated by NetworkManager
search datahead.biz
nameserver   8.8.4.4
nameserver   8.8.8.8
:x  (save & quit)

3.Restart The services

# systemctl enable  systemd-hostnamed
# systemctl restart systemd-hostnamed

# systemctl enable  network.service
# systemctl restart network.service
# systemctl restart NetworkManager

4.SetUp NameServers: Goto DNS Functions >> Edit Nameserver IPs

5.Restart the name server again

# systemctl restart named
Job for named.service failed because the control process exited with error code. See "systemctl status named.service" and "journalctl -xe" for details. 

So We are getting the same problem hat's why my parent domain and below the link is not accessible :

6. Follow >> CWP DNS Part 2