public class Presentation : ArcGIS.Desktop.Framework.Contracts.ViewModelBase, System.ComponentModel.INotifyPropertyChanged  

//Note: Call within QueuedTask.Run()
await QueuedTask.Run(() =>
{
  //Create mp4 format with appropriate settings
  MP4VideoFormat mp4Format = new MP4VideoFormat();
  mp4Format.Width = 800;
  mp4Format.Height = 600;
  mp4Format.OutputFileName = @"my folder\presentation.mp4";

  //Define Export Options
  PresentationExportOptions options = new PresentationExportOptions
  {
    PageRangeOption = ExportPageOptions.ExportByPageRange,
    CustomPages = "1,2,8"
  };

  //export as mp4
  presentation.Export(mp4Format, options);
});

//Must be on QueuedTask
await QueuedTask.Run(() =>
{
  // add a new image page in current active presentation
  var imagePage = presentation.AddImagePage("my image source", -1);

  // change the image source
  imagePage.SetImageSource("new image source");
});

//Must be on QueuedTask
await QueuedTask.Run(() =>
{
  // add a new video page in current active presentation
  var videoPage = presentation.AddVideoPage("my video file", -1);

  // change the image source
  videoPage.SetVideoSource("new video source");

  // change the start time of video to 3s
  videoPage.SetStartTime(3.0);
  // change the end time of video to 10s
  videoPage.SetEndTime(10.0);
});

//Must be on QueuedTask
await QueuedTask.Run(() =>
{
  // retrieve a map from the project based on the map name
  MapProjectItem mpi = Project.Current.GetItems<MapProjectItem>()
                             .FirstOrDefault(m => m.Name.Equals("Your Map Name", StringComparison.CurrentCultureIgnoreCase));
  Map map = mpi.GetMap();
  //create a map page using map's default extent
  presentation.AddMapPage(map, -1);

  //create a page using map's bookmark
  Bookmark bookmark = map.GetBookmarks().FirstOrDefault(
               b => b.Name == "Your bookmark"); // get the bookmark based on the bookmark's name
  presentation.AddMapPage(bookmark, -1);
});

ArcGIS.Desktop.Presentations.Events.PresentationEvent.Subscribe((args) =>
{
  var presentation = args.Presentation; //The presentation that was changed

  //Check what triggered the event and take appropriate action
  switch (args.Hint)
  {
    case PresentationEventHint.PropertyChanged:
      //TODO handle presentation property changed
      break;
    case PresentationEventHint.PageAdded:
      //TODO handle a new page added
      break;
    case PresentationEventHint.PageRemoved:
      //TODO handle a page removed from the presentation
      break;
    case PresentationEventHint.PageSettingChanged:
      //TODO handle page settings changed
      break;
  }
});

//For UI context changes associated with a presentation, subscribe to the PresentationView
//event - views activated/deactivated, views opened/closed
ArcGIS.Desktop.Presentations.Events.PresentationViewEvent.Subscribe((args) =>
{
  //get the affected view and presentation
  var view = args.PresentationView;
  var presentation = args.PresentationView?.Presentation;
  if (presentation == null)
  {
    //FYI presentationview and/or presentation can be null...
    //eg closed, deactivation
  }
  //Check what triggered the event and take appropriate action
  switch (args.Hint)
  {
    case PresentationViewEventHint.Activated:
      // Presentation view activated
      break;
    case PresentationViewEventHint.Opened:
      //A PresentationView has been initialized and opened
      break;
    case PresentationViewEventHint.Deactivated:
      // Presentation view deactivated
      break;
    case PresentationViewEventHint.Closing:
      //Set args.Cancel = true to prevent closing
      break;
    case PresentationViewEventHint.ExtentChanged:
      //presentation view extent has changed
      break;
    case PresentationViewEventHint.DrawingComplete:
      break;
    case PresentationViewEventHint.PauseDrawingChanged:
      break;
  }
});