Not able to run the POXMLP process from Peoplecode

Hi Team,

I am working on a requirement which need me to run the Print PO process through handler code of a rest service. I am getting the below error while calling the rest service.  I have checked the access group for the OPRID used for Anonymous node and that OPRId have access to Access group POALL which is the access group for POXMLP process. Can you suggest what else i might be missing?

Code:

  %This.createRunControl();

      Local ProcessRequest &prcs_rqst;

      &prcs_rqst = CreateProcessRequest("PSJob", "POXMLP");

      &prcs_rqst.RunControlID = &sRunContol;

      &prcs_rqst.Schedule();

Error:

"You are not authorized to run the multi-process job named POXMLP. (65,4) BC_SCM_PO_PRINT.CreatePO.OnExecute  Name:getPO  PCPC:807  Statement:18 Called from:XX_SCM_PO_PRINT.RequestHandler.OnExecute  Name:OnRequest  Statement:42"