Subdomain hosted in my VPS from a main domain that hosted on a different server cannot be given an SSL

Hi! I’ve recently installed Cyberpanel after deciding to host my own emails on a VPS. The VPS will be used solely for emails using webmail across all my websites.

I am able to point my VPS address to a subdomain mypanel.domain.com under my main domain of a website I host on a different server. For that I created a new website called mypanel.domain.com in Cyberpanel and added an A record in my DNS records, I was also able to issue a hostname ssl so I can now access Cyberpanel through mypanel.domain.com with SSL.

However I can’t seem to make it work for when creating a webmail page for each of the domains I own.
What I do is that I create a new website in Cyberpanel called domain2.com (to get DNS records) that I use to add in my domain service provider, I also create a webmail.domain2.com to point snappymail client to, both domain2.com and webmail.domain2.com I’m having a hard time issuing SSL. domain2.com is also hosted on a different server