Address container within a waypoint setup

How can I address my “db” container from my “backend” container in a two “app” setup in waypoint. Is there a way to set the name of the “db” app’s deployed container so that it can be referenced in another container?

I am using a single machine docker setup here.

waypoint.hcl

project = "nginx-http-golang-dev"

app "db" {
    config {
      env = {
        POSTGRES_USER = "postgres"
        POSTGRES_PASSWORD = "postgres"
      }
    }

    build {
      use "docker-pull" {
        image = "postgres"
        tag   = "13"
      }
    }

    deploy {
        use "docker" {
            name = db <-- this is not allowed
            service_port = 5432
        }
    }
}

app "backend" {
    path = "./backend"
    config = {
    	env = {
    		PG_DSN = "host=db\ port=5432\ user=postgres\ dbname=postgres\ sslmode=disable\ password=postgres" <-- I want to address my "db" container from here.
    	}
    }
    build {
        use "docker" {
        }
    }

    deploy {
        use "docker" {
            service_port = 80
            binds = ["${path.app}:/workspace:cached"]
        }
    }
}