ArcGIS Pro 2.6 API Reference Guide
Keyframes Property (Track)
Example 

ArcGIS.Desktop.Mapping Namespace > Track Class : Keyframes Property
Gets the collection of keyframes for the track.
Syntax
public IReadOnlyList<Keyframe> Keyframes {get;}
Public ReadOnly Property Keyframes As IReadOnlyList(Of Keyframe)
Example
Get the camera keyframes from the animation.
public List<CameraKeyframe> GetCameraKeyframes()
{
  var mapView = MapView.Active;
  if (mapView != null)
    return null;

  var animation = mapView.Map.Animation;
  var cameraTrack = animation.Tracks.OfType<CameraTrack>().First(); //There will always be only 1 CameraTrack in the animation.
  return cameraTrack.Keyframes.OfType<CameraKeyframe>().ToList();
}
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

Track Class
Track Members