PAID & UNPAID Amount - ISU

Good day,

Hi Experts,

My client's requirement is to get all Paid and unpaid customer from ISU.

PAID : from which table we need to extract the paid  amount.

Please correct me if i am wrong i am extracting from DFKKZP (BETRK).Is still we need to consider some point before extract from the table, please let me know.

UNPAID : how to get unpaid amount, please explain in detail.

Best Regards,

Naga.