The documentation page you linked to assumes that the ingress proxy is being deployed within your Kubernetes cluster. The sidecar is then injected for that pod, and runs alongside the ingress gateway.
In the case of the AWS load balancer controller, the ELB is created outside of your Kubernetes cluster, within the AWS infrastructure. As such, it is not possible for Kubernetes to inject an Envoy sidecar for the ELB instance. That is why the tutorial you referenced does not work on AWS.
In order to inject a Consul sidecar alongside your ingress, you will need to use a different ingress controller that deploys the ingress gateway within your Kubernetes cluster.
I hope this helps. Let me know if you have any further questions.