Exposing a ECS Service to the net

I have created a ECS cluster and created a number of services. But I want one of the services be accessed to the outside world. That service will then interact with the other services.

Created an ECS cluster Created services. Created the apps loaded into a docker container. I updated the security group to allow outside access

But under network interfaces on my console I cant find any reference to my security group I created. The security groups created are there.

resource "aws_ecs_service" "my_service" {
  name            = "my_service"
  cluster         = aws_ecs_cluster.fetcher_service.id
  task_definition = "${aws_ecs_task_definition.my_service.family}:${max(aws_ecs_task_definition.my_service.revision, data.aws_ecs_task_definition.my_service.revision)}"
  desired_count   = 0
  network_configuration {
    subnets         = var.vpc_subnet_ids
    security_groups = var.zuul_my_group_ids
    assign_public_ip = true
  }
}

Am I missing any steps

Thank you tp LRuttens answer. I set desired count to 1. and under network instances I see a network associated with my securitygroup for that ECS service,