A default domain name can be configured for all Knative Services. It's required if you want to enable auto-TLS.
domain_name: "kadras.io"
In scenarios where you don't have a domain name to use (for example, on a local environment), you can rely on the sslip.io
domain which redirects to the specified IP address.
domain_name: "127.0.0.1.sslip.io"
For more information, check the Knative Serving documentation on configuring domain names.