Returns a payable PDF export of the current user (exports of other users return 404).
Exports belong to the user, so the company-id header is not used.
Poll this endpoint every few seconds until status is completed, failed or expired.

Once completed, files holds one ZIP per company. Each files[].url is signed for
1 hour and is re-signed on every call, so request the export again if a link expired.
The ZIP files are purged 7 days after completion (status becomes expired, files is
empty). See POST /v1/erp/payouts/payables/pdf_exports for the ZIP layout, the
indice.csv format and a full polling example.