Google Tag - Event snippet for sales conversion page

Question

I am trying to implement a Google Tag from the PPC account of my clients. This code is on my sales conversion page. I believe I am along the right lines, but I'm not confident my PHP will pull in the correct Magento data.

I wish to insert the Value of the conversion and the Transaction ID.

<!-- Event snippet for Sales conversion page -->
<?php 
  $order_details = Mage::getModel('sales/order')->loadByIncrementId(Mage::getSingleton('checkout/session')->getLastRealOrderId());
  $adwords_saleamt = $order_details->subtotal;
  $transaction = Mage::getModel('sales/order_payment_transaction');
  $transaction_id = $transaction->setOrderId(1); 
?>
<script>
  gtag('event', 'conversion', {
  'send_to': 'XX-XXXXXXXXX/XXXXXXXXXXXXXX',
  'value': '<?php echo $adwords_saleamt; ?>',
  'currency': 'GBP',
  'transaction_id': '<?php echo $transaction_id; ?>'
});
</script>

Answer 1

please try this code

<?php
$OrderId = Mage::getSingleton('checkout/session')->getLastOrderId();
$Order = Mage::getModel('sales/order')->load($OrderId);
$incrementId = $Order->getIncrementId();
?>

<script>
 gtag('event', 'conversion', {
   'send_to': 'XX-XXXXXXXXX/XXXXXXXXXXXXXX',
   'value': <?php echo number_format($Order->getSubtotal(),2,".",""); ?> ,
   'currency': 'GBP',
   'transaction_id': <?php echo "'".$incrementId."'"; ?>
 });

</script>