HitPay–Zoho Commerce Integration

I run a Zoho Commerce store and want every order to flow through HitPay so customers in the Philippines can pay by card, QR, or their preferred local e-wallets. The scope is focused entirely on the checkout process: once the shopper clicks “Pay”, HitPay should handle the transaction and return the proper status back to Zoho so orders, stock levels, and confirmation emails behave just as they do with native gateways. During checkout I also need three additional data captures—customer notes, gift messages, and extra contact information. These custom fields must display cleanly in the storefront, pass through HitPay, and land inside Zoho Commerce’s order record so they remain visible in the admin panel and in exported reports. I already have merchant credentials from HitPay; you will just need to wire them up using Zoho Commerce’s Payment Gateway API or a custom extension, test end-to-end in sandbox, and then push live. Please build with future upgrades in mind and document any scri...