Thanks Clemens!
The wrapper method worked. However facing another issue now. Trying to fetch the results(BAPIRETURN) of the wrapper FM using RECEIVE RESULTS FROM FUNCTION but it raises a short dump. Any idea on this?
RECEIVE RESULTS FROM FUNCTION 'Z_RWB_UPD_SERV_ORDER'
TABLES
it_ret = et_ret.
Short Dump:
Error when receiving answer to a Remote Function Call.
Error analysis
Internal error: Invalid RFC handle.