Oh, my silly …
I thought that, for whatever reason, my domain (virtual host) via certbot would request a certificate from let’s encrypt! But as far as I understand it - it is not like that, but please correct me if you can ask for a let’s encyrpt certificate for a virtual host with the standard nethserver modules / settings !?
Otherwise, my IPv4-to-IPv6 https proxy organizes a certificate - only there was a problem …
So thank you, and I have once again dealt with the topic a little bit!
Best regards
Martin