EPT(Enterprise Project Type) creation using workflow service. How to fix error - EnterpriseProjectTypeAtLeastOnePDPIsRequired

I'm trying to create EPT using workflow.svc but not able to resolve the below error.  

"ProjectServerError(s) LastError=EnterpriseProjectTypeAtLeastOnePDPIsRequired Instructions: Pass this into PSClientError constructor to access all error information"

Here is the code which i wrote - 

// Workflowdataset
            backendWorkflow.WorkflowDataSet dsNewEPT= new backendWorkflow.WorkflowDataSet();
       
            //EnterpriseProjectTypeRow
              backendWorkflow.WorkflowDataSet.EnterpriseProjectTypeRow row =
                    dsNewEPT.EnterpriseProjectType.NewEnterpriseProjectTypeRow();

            row.ENTERPRISE_PROJECT_TYPE_NAME = "TestEPT";
            Guid guidEpt = Guid.NewGuid();
            row.ENTERPRISE_PROJECT_TYPE_UID = guidEpt;
            row.ENTERPRISE_PROJECT_WORKSPACE_TEMPLATE_NAME = "PWS#0";
            row.IS_DEFAULT_PROJECT_TYPE = true;
                        
            dsNewEPT.EnterpriseProjectType.AddEnterpriseProjectTypeRow(row);

            //EnterpriseProjectTypePDPsRow
            backendWorkflow.WorkflowDataSet.EnterpriseProjectTypePDPsRow rowPDP =
                dsNewEPT.EnterpriseProjectTypePDPs.NewEnterpriseProjectTypePDPsRow();

            rowPDP.ENTERPRISE_PROJECT_TYPE_UID = guidEpt;
            rowPDP.PDP_UID = new Guid("a0e7da7e-e035-47e2-bb45-0f1005ee695f");
            rowPDP.PDP_ID = 4;
            rowPDP.PDP_POSITION = 0;
            rowPDP.IS_CREATE_PDP = true;

            dsNewEPT.EnterpriseProjectTypePDPs.AddEnterpriseProjectTypePDPsRow(rowPDP);

            //CreateEnterpriseProjectType
            workflowClient.CreateEnterpriseProjectType(dsNewEPT);

I'm looking for guidance to resolve this issue. Any help in this regard will be much appreciated.