Purchase dataLayer.push

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
  event: 'purchase',
  ecommerce: {
    currency: 'EUR',
    value: 109.29,
    tax: 7.18,
    shipping: 10.00,
    affiliation: 'My Parka Store',
    transaction_id: 'p115-20202000',
    coupon: 'free_back_rub',
    items: [{
      item_name: 'Finnish magical parka',
      item_id: 'mp1122',
      price: '31.10',
      item_brand: 'PARKA4LIFE',
      item_category: 'Apparel',
      item_category2: 'Coats',
      item_category3: 'Parkas',
      item_category4: 'Unisex',
      item_variant: 'Navy blue',
      quantity: '3'
    },{
      item_name: 'Parka stain removal',
      item_id: 'psr1332',
      price: '5.99',
      item_brand: 'PARKA4LIFE',
      item_category: 'Apparel',
      item_category2: 'Utility',
      item_category3: 'Care product',
      quantity: '1',
      item_coupon: 'cheap_stain_removal'
    }]
  }
});