How to Post WPUFIB in ECC without POSDM?

Dear Experts,

Our client will deploy new e-commerce website. The data need to be parsing to SAP.

We have an idea to get the data from e-commerce with xml file. XML file will be parsing from SPROXY.

Then PI get the data, and transferred them by IDOC WPUFIB to create accounting document.

ABAPer use function module IDOC_INPUT_POS_FINANCIAL_ACC to create idoc WPUFIB in ECC.

But, the result is an outbound idoc created. It supposed to be an inbound idoc.

How to use function module IDOC_INPUT_POS_FINANCIAL_ACC so the idoc created is the inbound one?

Thanks for the help before.

Best regards,

Rosida