public LayerCreationParams( 
   Uri uri
)

      //Connect to the AGS service. Note: the connection will persist for the
      //duration of the Pro session.
      var serverUrl = "https://sampleserver6.arcgisonline.com/arcgis/rest/services";

      var username = "user1";
      var password = "user1";

await QueuedTask.Run(() =>
{
  //at any point before creating a layer, first make a connection to the server
  //if one has not been already established for the current session
  var uri = new Uri(serverUrl);
  var props = new ServiceConnectionProperties(uri)
  {
    User = username
  };
  //It is preferred that you use the Windows Credential Manager to store the password

  //However, it can be set as clear text if you so choose
  props.Password = password; //not recommended

          //Establish a connection to the server at any point in time _before_
          //creating a layer from a service on the server
          var gdb = new Geodatabase(props);
  gdb.Dispose();//you do not need the geodatabase object after you have connected.
});

      //later in the session, as needed...create a layer from one of the services
//on the server
      var serviceUrl = "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Wildfire_secure/MapServer";
var map = MapView.Active.Map;

      QueuedTask.Run(() =>
      {
          var lc = new LayerCreationParams(new Uri(serviceUrl));
          LayerFactory.Instance.CreateLayer<MapImageLayer>(lc, map);
      });

var sceneLayerUrl = @"https://myportal.com/server/rest/services/Hosted/SceneLayerServiceName/SceneServer";
//portal items also ok as long as the portal is the current active portal...
//var sceneLayerUrl = @"https://myportal.com/home/item.html?id=123456789abcdef1234567890abcdef0";

await QueuedTask.Run(() =>
{
  //Create with initial visibility set to false. Add to current scene
  var createparams = new LayerCreationParams(new Uri(sceneLayerUrl, UriKind.Absolute))
  {
    IsVisible = false
  };

  //cast to specific type of scene layer being created - in this case FeatureSceneLayer
  var sceneLayer = LayerFactory.Instance.CreateLayer<Layer>(
           createparams, MapView.Active.Map) as FeatureSceneLayer;
  //or...specify the cast directly
  var sceneLayer2 = LayerFactory.Instance.CreateLayer<FeatureSceneLayer>(
           createparams, MapView.Active.Map);
  //ditto for BuildingSceneLayer, PointCloudSceneLayer, IntegratedMeshSceneLayer
  //...
});