post https://api-sandbox.ezypay.com/v2/billing/futureinvoices/recordpayment
Record payment from a customer that occurred outside the Ezypay system (for example an over-the-counter cash transaction) on a future invoice of a subscription.
Ensures payments collected in advance externally from Ezypay can be reconciled and marked as paid. The future invoice will be issued immediately in advance as a paid invoice, with an external payment type recorded against it.