grpc-gateway service not responding to grpcurl or curl

Question

I have created a basic service with grpc-gateway. This is what my .proto file looks like

syntax = "proto3";

package health;

option go_package = "github.com/userl/brw/api/health";
import "google/api/annotations.proto";

service Health {
    // Sends a greeting
    rpc Ping (HealthRequest) returns (HealthReply) {
      option (google.api.http) = {
        get: "/ping"
      };
    }
  }
  
  // The request message containing the user's name
  message HealthRequest {    
  }
  
  // The response message containing the greetings
  message HealthReply {
    string message = 1;
  }

I generate and start the service with the following code

mux := runtime.NewServeMux()
opts := []grpc.DialOption{grpc.WithInsecure()}
err := pHealth.RegisterHealthHandlerFromEndpoint(ctx, mux, ":3002"), opts)
if err != nil {
    log.Fatal(err)
}

http.ListenAndServe(":3001"), mux)

Now when I try to curl command for example on curl http://localhost:3001/ping I get the following error curl: (7) Failed to connect to localhost port 3003: Connection refused

When I tried grpcurl grpcurl --plaintext localhost:3002 list I get the following error failed to dial target host "localhost:3002": dial tcp 127.0.0.1:3002: connect: connection refused

Not sure what is going wrong here or what I need to do.