PaymentCompletionCallback typedef

Callback invoked when the payment process has finished.

This callback takes no parameters and is triggered when the payment browser redirects back to the application, indicating that the payment process has been completed or aborted.

IMPORTANT: This callback only indicates that the payment flow has finished in the browser. It does NOT guarantee that the payment was successful. The application MUST verify the payment status with the server after receiving this callback.

Example:

void onPaymentComplete() {
  // Verify payment status with your server
  checkPaymentStatus(orderId);
}