Add a second server to my Domain

**Operating system: Debian
**OS version: 10

Hi there,

I have a question. I just bought a second VPS server. I want to add them to my installation. My main problem at the moment is, how can I add the second server to my main domain?
Let’s say I have for example the domain: example.com.

Example.com is hosted on server 1. Which is also my Nameserver 1 (ns01).
The new server should be reachable. I put a hostname (secondary.example.com) to it and installed Virtualmin. I updated my DNS on Server1, I added the secondary.example.com and point it to the new server 2.
How can I make it possible to issue a valid SSL certificate for my new Server2? Do I need to create a new Virtual Server on Virtualmin on Server 2?

Thanks a lot community