ArcGIS Pro 2.8 API Reference Guide
Heading Property (Camera)
Example 

ArcGIS.Desktop.Mapping Namespace > Camera Class : Heading Property
Gets or sets the Heading of the Camera, in degrees from North. 0 is North, 90 is West, 180 is South, -90 is East, etc. This property applies to both 2D and 3D views.
Syntax
public double Heading {get; set;}
Public Property Heading As Double
Remarks

Heading, Pitch and Roll are used to describe the viewing direction in a 3D view. Sometimes referred to as Yaw, Heading defines the angle of the camera rotating around the Z-axis. Imagine yourself as the camera. In this case adjusting the heading would be equivalent to looking to the left or right. The valid range for heading is -180 to 180 which are equal looking south. A value of 0 is looking north.

Heading is the one viewing direction property that is also used in 2D view. In a 2D view Heading determines and will determine the rotation of the view.

Example
Rotate the active map view.
public void RotateView(double heading)
{
  //Get the active map view.
  var mapView = MapView.Active;
  if (mapView == null)
    return;

  //Get the camera for the view, adjust the heading and zoom to the new camera position.
  var camera = mapView.Camera;
  camera.Heading = heading;
  mapView.ZoomToAsync(camera, TimeSpan.Zero);
}
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

Camera Class
Camera Members