After payment the customer is redirected to a result page. Create one page per gateway you use and select it in Settings → Payment Settings (“… Success Page”):
[wpgv_giftvouchersuccesspage]: PayPal and bank transfer / invoice[wpgv_stripesuccesspage]: Stripe[wpgv_klarnasuccesspage]: Klarna[wpgv_molliesuccesspage]: Mollie[wpgv_giftvouchercancelpage]: shown when the customer cancels or the payment fails
The success page verifies the payment with the gateway, marks the voucher as paid, shows the download link and triggers the emails. The messages on both pages are editable under General Settings → Successful Page Message / Order Cancellation Message. With WPML or Polylang the plugin uses the translated page that matches the customer’s language.