[A] The reason export invoices are not visible in the Payments module could be that you have not converted export invoice or commercial invoice to INR invoice.
[B] In order to show foreign currency invoices in the Payments module, the export invoices should have their values converted in the Indian currency.
[C] To prepare an INR invoice, go to the export invoice for you are facing this problem.
[D] Go to "OTHER ACTIONS" (1) and click on "Prepare INR Invoice"(2).
[E] A new form will open. This form will have an option of currency rate which will be used for conversion. It can be reset. Other details remain the same as the original export invoice.
[F] Once done, click on Save and Send. The Payments module will now show this export invoice.
Keywords - foreign currency to INR, export invoice not showing in payments