RV_INVOICE_CREATE is not a BAPI and this function is not released to the customers.
Unless the immediate invoice creation is an absolute "must have" you might also want to consider just running Billing Due List (SDBILLDL) separately and let it take care of the billing process. It's the process that many (if not most) SAP customers use. Otherwise if there is an error you'd have to rely on someone not just to correct the error but also create an invoice manually.