Metrics not working :(

MainServer.scala

object MainServer extends TwitterServer {
  override def failfastOnFlagsNotParsed: Boolean = true

  // some flags received via config
  val port: Flag[Int] = flag("port", 8081, "TCP port for HTTP server")

  // logging formatter
  override def defaultFormatter = new Formatter(
    timezone = Some("UTC"),
    prefix = "<yyyy-MM-dd HH:mm:ss.SSS> [%.3s] %s: "
  )

  // some stats
  val echosProcessed: Counter = statsReceiver.counter("echos_processed")
  val getEchosLatency: Stat   = statsReceiver.stat("get_echos_latency")

  // sample endpoint
  val echo: Endpoint[String] = get("echo" :: string) { (phrase: String) =>
    Stat.time(getEchosLatency) {
      log.debug(s"Received a request for 'echo' at ${Time.now}")
      echosProcessed.incr()
      Ok(phrase)
    }
  }

  // Public server API (for customers)
  val api: Service[Request, Response] = echo.toService

  def main(): Unit = {
    log.info("Serving the Questionnaire application")

    val server =
      Http.server
        .withStatsReceiver(statsReceiver)
        .withLabel("questionnaire-server")
        .withRequestTimeout(Duration.fromSeconds(30))
        .serve(s":${port()}", api)

    onExit { server.close() }

    // launches admin server
    Await.ready(adminHttpServer)
  }
}