docs: def api_notifications():
      """Receive MTurk REST notifications."""
      event_type = request.values['Event.1.EventType']
      assignment_id = request.values['Event.1.AssignmentId']
  
      # Add the notification to the queue.
      db.logger.debug('rq: Queueing %s with id: %s for worker_function',
                      event_type, assignment_id)
      q.enqueue(worker_function, event_type, assignment_id, None)
      db.logger.debug('rq: Submitted Queue Length: %d (%s)', len(q),
                      ', '.join(q.job_ids))
  
      return success_response(request_type="notification")