The Lumen platform only accepts requests with a domain name that is explicitly added to an environment. For example, if you add www.example.com to Lumen as www.example.com but then choose to create a blog.example.com CNAME record pointing at www.example.com.c.section.io., visitors to http://blog.example.com will receive an error page showing HTTP 409 Conflict.
This is because blog.example.com has not been explicitly associated with a Lumen environment. In this case you would need to add blog.example.com to a Lumen environment and then create a blog.example.com.c.section.io CNAME record for blog.example.com in your DNS hosting console. The same is true if you register a bare domain record such as example.com. Each domain must be specified in full in order for the request to be accepted by Lumen.
If you would like your Lumen application to respond to multiple domains, you can add them on bottom of the Domains page under Domains. You can also add or delete additional domains using our API: