Additional Sub-Domain with SSL?

I set up a new sub-domain in the “Custom DNS Records”-Panel.
But I can’t setup a SSL-Certificate in the “SSL-Certificates”-Panel for that subdomain. Isn’t that possible?


Remove the custom DNS records. Instead add a mail user or a mail alias.

did you get this set up correctly using external dns for sub-domain? if so, can you post to the topic I just created?