The forum is dedicated to discuss lesson related inquiries and due to the shortage of time resources this policy is strictly followed.

I can share my thoughts on how accounting data is usually extracted from AP and could be transferred to external systems as pertains to the topics covered.

In R12 the AP module simply pass accounting events to SLA module.

The accounting is created by SLA module and accounting entries are then transferred from SLA to General Ledger module.
All this is covered in SLA videos.

Therefore the two logical places to pick up accounting data are: SLA table XE% and GL tables GL%.
GL tables makes up the best place to pick up the entries from as this way you only retrieve what is posted in GL and hence reflected in financial statements.
select * from gl_je_headers a, gl_je_lines b
where je_source = 'Payables'
and status = 'P' -- Posting flag
and ledger_id = <X>
(The SQL is written on the fly and not tested).