Hi Bhargava,
The FM which you created, has this been mapped in table TPS34? If yes , you created ZFM by copying OPEN_FI_PERFORM_CRM0_200_P? It should trigger then As a starting point you can start the debug from FM - CRS_SEND_TO_SERVER , Inside it we have call to OPEN_FI_PERFORM_CRM0_200_P . This FM calls the entry which we maintained in TPS34.
BR/Himayat