Solve Vehicle Routing Problem - API for Python

[Teejay]

Hi All,

I am just running to use Solve Vehicle Routing Problem ESRI provided in Solve Vehicle Routing Problem—ArcGIS Pro | Documentation  

I have same data and no changes made. I just use the same code. But when I am getting the following error at 

routes = arcpy.GetParameterValue("SolveVehicleRoutingProblem_na",2)
routes.load(inRoutes)

I tried using ArcMap 10.5 and ArcGIS Pro 2.3. Can someone point me in the right direction?