NS records

I had a domain name I used for Webmin and I do not have it more and now I have changed the domain. on the server, I have changed the hostname. now when I type the new domain name:10000 I can get to Webmin but when I create a new virtual server and want to add letsencrpt I get the error Bind can not resolve the old domain name. how can I get bind to see my current domain name. I get this issue just when I need to install letsencrypt

Virtualmin version: 
Webmin version: 


Assigned: ยป Unassigned

What is the exact error message that you're getting?

this is what i get Validating configuration for el.sesolutions.se .. .. errors were found, which will prevent Let's Encrypt from issuing a certificate : BIND DNS domain : NS record portal.wedding2020.net. cannot be resolved to an IP address

Ok, that could be a problem. If you choose the option to skip validation when requesting the cert, does it work?