Reverse document with BAPI_ACC_DOCUMENT_REV_POST

Hi all,

I want to reverse FI document with BAPI_ACC_DOCUMENT_REV_POST for documents that was posted with BAPI_ACC_DOCUMENT_POST, but it showed this error: OBJ_SYS is missing. How do we set the data for OBJ_SYS, OBJ_TYPE, and OBJ_KEY?

I tried to fill in with something similar with the one when we do manual posting, but it's still showed error.

Please help,

Meila