GA4 - begin_checkout - next

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
  event: 'begin_checkout',
  ecommerce: {
    items: [{
      item_name: 'ECLIPSE Blackoil Reservoir Simulation',         //Product Name - Type: string
      item_id: '71274',                         //Product ID/SKU - Type: string
      price: 4000.00,                           //Product price - Type: number
      currency: 'USD',                          //Currency of the price that is collected - Type: string
      discount: 0.00,                           //Any discount associated with this product - Type: number
      item_brand: 'Oil and Gas Software',       //Product Brand - Type: string
      item_category: 'Schlumberger Software',   //Product Category - Type: string
      item_category2: 'Indonesia',              //Product Sub-Category 1 - Type: string
      item_category3: 'Jakarta',                //Product Sub-Category 2 - Type: string
      item_variant: 'Foundation',               //Variant of the product - variant SKU/ID - Type: string
      quantity: 1                               //Product quantity - Type: number
    },{
      // Another item.
    }]
  }
});