Hi Babu Y
Can u please mention the meaning of prepayment and prepayment invoice?
What is ur accounting entry posted in FB01?
Document type KZ is used for posting the payment document to vendor. You already paid to vendor by using FB01 with doc type KZ. Now how is possible to run APP for that document?
If you have any pending invoices(which are posted in Doc. type KR) of the vendor or if u have any down payment request made by vendor, then only u can run APP.
Your question is not clear. Revert with exact requirement.
Regards,
Singaiah Pathuri(singh)