The 1.18 release note explains how to change the Kourier service type and defaultExternalScheme as below:

spec:
  ingress:
    kourier:
      service-type: LoadBalancer

spec:
  config:
    network:
      defaultExternalScheme: "http"

But the release note will be archived in the future.

We continue to support the configurations. So these configurations should be added to Configuring the Knative Serving custom resource section.