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, .
To guarantee the security of the exchange, the data is signed with a certificate only known to the merchant and the payment gateway.