How can i use cloud armor on nginx ingress controller?

First of all, I am using an Nginx ingress controller with the helm for the gke and I am using ModSecurity as a waf. Nevertheless, I was researching for a new kind of waf to display the results of prevention, and cloud armor looks like what I am looking for. Unfortunately, it works only with HTTP/HTTPS Load Balancers but my Nginx ingress external load balancer is a TCP load balancer. As far as I research, I can't convert this load balancer's protocol TCP to HTTP/HTTPS.

- First Question, Is this conversation possible and if it is possible, Can I use cloud armor on it.

Secondly, I tried to create a new cloud load balancer to route traffic through it. Unhappily, Even I can active cloud armor on it, Routing is not working as I expected because it returned me 502 anyway even if it health checks look okay.

Finally, i tried to use BackendConfig with yaml :

apiVersion: cloud.google.com/v1beta1
kind: BackendConfig
metadata:
  name: armor-backendconfig
spec:
  securityPolicy:
    name: "bla-armor"

apiVersion: v1
kind: Service
metadata:
  annotations:
    cloud.google.com/backend-config: '{"ports": {"443":"bla-backendconfig"}}'
spec:
  clusterIP: xx.xx.xx.xx
  externalTrafficPolicy: Local
  healthCheckNodePort: xxxxxxx
  loadBalancerIP: xx.xx.xxxx.xx
  ports:
   - name: http
     nodePort: 31000
     port: 80
     protocol: TCP
     targetPort: http

And it doesn't work again. That was my last hope. Is there any advice for here?