Complex PO Updation using Purchase Document Open Interface PDOI

Hi,

We have below requirement to Add new Pay Items in Existing Line in Existing Complex PO in R12.1.3.

I can add new Line and new Payitems in Existing Complex PO but getting error while adding New Payitems in Existing Line.

Please let me know if we can achieve above using PDOI interface or there is any other way we can add new Payitem in existing line from Backend.

Regards

Udit Manchanda