Virtualmin needs added to the list of DNS servers, but doesn't save

I installed Virtualmin 4.10.gpl GPL and check the configuration.
I received message:
Virtualmin is configured to setup DNS zones, but this system is not setup to use itself as a DNS server. Either add to the list of DNS servers, or turn off the BIND feature on the module config page.
… your system is not ready for use by Virtualmin.

I select the link, list of DNS servers > I add to the list of DNS servers > Save > Apply Configuration > System Information > Re-check and refresh configuration > and same error.

Any suggestions please?

I fixed this.
You need to change the DNS settings in CentOS.