public void StartStreaming()

var url = "https://geoeventsample1.esri.com:6443/arcgis/rest/services/AirportTraffics/StreamServer";
     
await QueuedTask.Run(() =>
{
  var realtimeServiceConProp = new RealtimeServiceConnectionProperties(
                                   new Uri(url),
                                   RealtimeDatastoreType.StreamService
                                );
  using (var realtimeDatastore = new RealtimeDatastore(realtimeServiceConProp))
  {
    //A Realtime data store only contains **one** Realtime feature class (or table)
    var name = realtimeDatastore.GetTableNames().First();
    using (var realtimeFeatureClass = realtimeDatastore.OpenTable(name) as RealtimeFeatureClass)
    {
      //feature class, by default, is not streaming (opposite of the stream layer)
      realtimeFeatureClass.StartStreaming();
      //TODO use the feature class
      //...
    }
  }

});