Yes, I used the method they describe in that page, particularly: "Register your resource metrics API and your custom metrics API with the API aggregation layer

Yes, I used the method they describe in that page, particularly: "Register your resource metrics API and your custom metrics API with the API aggregation layer. Both of these API servers must be running on your cluster." The blogpost goes through the implementation of the required "custom-metrics-api" and how to plug this new API server in your existing Kubernetes environment.