Coolify would generate SSL certificates for your resources if you defined the URL starting with HTTPS.
Coolify using Let's Encrypt helper. Only used if you use Coolify Proxy.
www vs non-www
Certificates are only generated for the defined URL. If you specify a non-www URL, only the non-www will have a certificate. You cannot reach the www URL.
Usually, you need to redirect www to non-www on the DNS layer.
If you would like to generate SSL certificates for both, there is an option called
Generate SSL for www and non-www? for applications and services.