I have a domain name (www.my_domain.com), and this is attached to a load balancer in GCP. I have a google managed SSL-certificate for the frontend service of this load balancer. This works perfectly.
I now want to deploy a litespeed/wordpress image/instance on GCP deployments manager. I want this website to be available on https://web.my_domain.com, hence a subdomain.
When deploying, I get the public IP of the deployment. I add this to my DNS-settings for the domain name as an A-record (A web.my_domain.com. SERVER_IP). When visiting http://web.my_domain.com, I can see the website. Note it's http, not https.
I now want to add a SSL-certificate for this subdomain. When SSH'ing into the litespeed server, I get a setup prompt. It asks me for the domain name. I enter "web.my_domain.com". Then, it asks me if I want to setup a SSL-certificate with Let's Encrypt. It asks for the domain name, and it will setup an SSL-certificate for the www-version and the non-www-version. But this is not what I want. I want a SSL-certificate for a subdomain. When I enter "web.my_domain.com", it automatically searches for "www.web.my_domain.com", because it thinks web.my_domain.com is the "main" domain and not a subdomain.