Program RFBIBLK0 posts request documents into the system that have been created outside the SAP R/3 system.

For detailed information, see the program documentation Request Transfer from Preprocedure (RFBIBLK0).

If you want to transfer requests from preprocedures into your R/3-System, you have to call the data transfer workbench (transaction sxda) and select the object type accounting document (BKPF).