add_to_wishlist Event

window._upstack('track', 'add_to_wishlist', {
  items: [
    {
      id: 'SKU_12345',
      name: 'Classic Cotton Tee',
      price: 34.99,
      brand: 'Example Brand'
    }
  ],
  value: 34.99,
  currency: 'USD'
});