How enable backend Keepalive using TCP from LoadBalancer kubernentes?

Hi, I’m trying to enable keep-alive support from a LoadBalancer for an Ingress Controller in kubernetes:

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/do-loadbalancer-enable-proxy-protocol: "true"
    # service.beta.kubernetes.io/do-loadbalancer-enable-backend-keepalive: "true"
  labels:
    helm.sh/chart: ingress-nginx-2.11.1
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/version: 0.34.1
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/component: controller
  name: ingress-nginx-controller
  namespace: ingress-nginx
spec:
  type: LoadBalancer
  externalTrafficPolicy: Local
  ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: http
    - name: https
      port: 443
      protocol: TCP
      targetPort: https
  selector:
    app.kubernetes.io/name: ingress-nginx
    app.kubernetes.io/instance: ingress-nginx
    app.kubernetes.io/component: controller

The issue is that KeepAlive is only available for “HTTP” forwarding rule, ending with this error:

Backend keepalive requires at least one forwarding rule with HTTP or HTTPS target protocol.

BUT ports only support “TCP”, “UDP”, and “SCTP” protocols. Default is TCP.

So, how get this enable?