How to delete a created ns - nameserver record

Dear sirs,

Where can I modify/delete ns records created via DNS >> create nameserver?

What I did:

  • main >> website >> create website
  • main >> DNS >> create nameserver

I went to the created website >> manage >> added a domain.

I uploaded an index file onto the subdomain >> public_dir and YES, subdomain resolves, etc.

Sample file uploaded into the the domain >> public_dir; main domain also resolves fine.

Now trying to setup a mailserver, followed this tutorial:
section 4B also says to create nameserver

My mailserver is up and running, however I just discovered that the IP assigned is blacklisted.

I have modified the IPs that my registered domains ns1 and ns2 are pointing to - at the domain registrar panel,

Now I need to make the necessary changes in Cyberpanel.

I have checked DNS >> add/delete records >> select domain >> NS tab… however there are no records listed there.

Pls help / clarify