how to change primary domain?

Hello, my url to panel says let say bookinmacedonia.com , but bookinmacedonia.com is used for DNS adresses in my CWP
like ns1 and ns2. I have premium version of CWP but i can't find a way to change it let say to another domain also when i create subdomain to put as mail server and hostname it says error.
Please if somebody can help me out with this.

Thanks & Kind Regards

Hi, try to use the hostname to log in to CWP.