SDK where do I find payments linked to invoices

SOLVED

I am using Pastel V19 SDK to draw data because the client requires specialised Customer Statements.  Using the ACCTRN combined with the ACCMASD files I can get all the transactions that must be displayed on the statement (I had to import from previous year files to ensure I had the correct opening balances).

On Pastel the users link payments to specific invoices, which results in the Pastel statement pairing payments to invoices.

Does anyone know where I can find this payment to invoice link in the data using the SDK?

I have sent an email to sdksupport, but they take a very long time to respond (weeks), and sometimes doesn't respond at all.

Any assistance will be welcome.