Virtualmin Subdomain DNS creation errors

SYSTEM INFORMATION
OS type and version: Centos 7
Webmin version: 1.973
Virtualmin version: 6.16

I have an issue creating a subdomain for my web domain and managing complete dns for my entire domain. I need to be able to have full DNS management so that I can create subdomains and other.

I downloaded VirtualMin and created a new virtual server. I did not touch anything else.

I first tired pointing A and www DNS records to my IP address through my domain name provider. This allows me to manage DNS but I want to manage it within VirtualMin (as I don’t want to create new records every time I want a subdomain).

I’m trying to link my main domain to VirtualMin. I set up nameservers with my domain name provider which point to my IP address via ns1.example.com and ns2.example.com.

This allows me to access my main website, but when I create a subdomain, the domain does not resolve. I’m not sure how the DNS worked for mine, I created a master zone through BIND for both of my domains. The DNS looks like this for example.com: (all pointing to my IP)

example.com
www.example.com
mail.example.com
ftp.example.com
ns1.example.com
ns2.example.com
test1.example.com
www.test1.example.com
ftp.test1.example.com
m.test1.example.com
webmail.test1.example.com
admin.test1.example.com
mail.test1.example.com

I only want to be able to create a subdomain and manage DNS within Virtualmin. I search up tutorials online but they are all different. Can someone give me a clear example on how to create a subdomain and link my domain to my VirtualMin server using nameservers (not my registrar’s dns) ?