ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Desktop.Layouts Namespace / Layout Class / SendToBack Method

SendToBack Method (Layout)
Overload List
OverloadDescription
Send the element to the back of its parent's element collection. This method must be called on the MCT. Use QueuedTask.Run.  
Send the elements to the back of their parent's element collection. This method must be called on the MCT. Use QueuedTask.Run.  
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.7 or higher.
See Also