Saved payment & upsell

PaySightSDK.createWidget({
  targetId: 'payment-container',
  config: {
    productId: YOUR_PRODUCT_ID,
    sessionId: 'checkout-' + Date.now(),
    environment: 'sandbox',
    amount: 29.99,
    savePaymentMethod: true,
    customer: { email: 'customer@example.com', country: 'US' },
  },
  onMessage: (msg) => {
    if (msg.type === 'PAYMENT_SUCCESS') {
      const session = msg.payload?.paysightSession;
      sessionStorage.setItem('paysightSession', session);
      window.location.href = '/upsell';
    }
  },
});

const paysightSession = sessionStorage.getItem('paysightSession');

PaySightSDK.createWidget({
  targetId: 'upsell-container',
  config: {
    productId: YOUR_PRODUCT_ID,
    sessionId: 'upsell-' + Date.now(),
    environment: 'sandbox',
    amount: 9.99,
    usePreviousPaymentMethod: true,
    upsell: {
      upsellId: 'addon-offer',
      initialPaymentSession: paysightSession,
      upsellButton: { text: 'Add to order' },
    },
    customer: { email: 'customer@example.com' },
  },
  onMessage: (msg) => {
    if (msg.type === 'PAYMENT_SUCCESS' && msg.payload?.mode === 'upsell') {
      redirectToThankYou();
    }
    if (msg.type === 'DUPLICATE_TRANSACTION') redirectToThankYou();
    if (msg.type === 'PAYMENT_ERROR' && msg.payload?.mode === 'upsell') {
      showError(msg.payload);
    }
  },
});

widget.submitUpsell();

upsell: {
  upsellId: 'addon-offer',
  initialPaymentSession: paysightSession,
  threeDSRequired: true,
  cancelOnThreeDSFailure: true,
  failOnThreeDSChallenge: false,
}