Magento – Magento2 Google analytics Conversion data on success page

I have a magento2.2.5 based website and even though I have Google analytics and adwards enabled I dont see conversion data.

So I spoke with google and was given the below code. However I do not know how to look through purchased items on the order success page and looking for suggestions??

 //getting order data
   $order = Mage::getModel('sales/order')->load($this->getOrderId());
   $grandtotalis = $oOrder->getGrandTotal();
   $grandtotalis = number_format($grandtotalis, 2, '.', '');
   $shipping = $oOrder->getShippingAmount();
   $tax = $oOrder->getTaxAmount();
   $store = Mage::app()->getStore();
   $thestorename = $store->getName();

<!-- Global site tag (gtag.js) - Google Ads: 789798816 -->

window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());

gtag('config', 'abcdefg');

 <!-- Event snippet for Sales Conversion New conversion page -->
 <script>
    gtag('event', 'conversion', {
         'send_to': 'ffff',
         'value': <?php echo "$grandtotalis"; ?>,
         'currency': 'USD',
         'transaction_id': '<?php echo $block->getOrderId();?>'
    });
 </script>
 <script type="text/javascript">
    ga('require', 'ecommerce');
    ga('ecommerce:addTransaction', {
       'id': '<?php $block->getOrderId(); ?>',   //Transaction ID. Required.
        'affiliation': '<?php echo "$thestorename":?>',   // Affiliation or store name.
        'revenue': '<?php echo "$grandtotalis";?>',               // Grand Total.
        'shipping': '<?php echo "$shipping";?>',                  // Shipping.
        'tax': '<?php echo "$tax";?>'                     // Tax.
   });

    ga('ecommerce:addItem', {
       'id': '<?php $block->getOrderId(); ?>',       // Transaction ID. Required.
       'name': 'Fluffy Pink Bunnies',    // Product name. Required.
       'sku': 'DD23444',                 // SKU/code.
       'category': 'Party Toys',         // Category or variation.
       'price': '11.99',                 // Unit price.
       'quantity': '1'                   // Quantity.
    });

   ga('ecommerce:send');
</script>