ArcGIS Pro 3.0 API Reference Guide
ArcGIS.Desktop.Core Namespace / ProApp Class / ProjectFileExtension Property

ProjectFileExtension Property (ProApp)
Gets the project file extension
Syntax
public override string ProjectFileExtension {get;}
Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

ArcGIS Pro version: 2.4 or higher.
See Also