I am still confused about what you are trying to do.
If you speak about the Datasmith SDK Exporter Datasmith Export Sdk Guidelines | Unreal Engine 5.4 Documentation | Epic Developer Community
Its purpose is to provide a way to export UE’s datasmith exchange format of .udatasmith to load in UE based applications. Apart from UE or Twinmotion I am not aware of any other application supporting that format on import.
If you want to export 3d models from your custom application to Blender, I would recommend looking for an industry standard, widely used format such as glTF or USD (or even obj or FBX).