Establishing interaction with the payment gateway
The merchant website and the payment gateway interact by exchanging data.
To create a payment, this data is sent in an HTML form via the buyer's browser.
- automatically by means of a notification called Instant Notification URL (also called IPN), see chapter Setting up notifications,
- via the browser when the buyer clicks on the button to return to the merchant website, see chapter Managing the return to the merchant website.
To guarantee the security of the exchange, the data is signed with a certificate only known to the merchant and the payment gateway.