Display WooCommerce Order Number and Order Total in the HEAD tag of order received page

I am trying to add WooCommerce order number and order total to the head tag of thank you page. Here is my code I have in header.php

<?php if(is_wc_endpoint_url( 'order-received' )){ 
global $woocommerce;
$orderid = $woocommerce->order->get_id();
$ordertotal= $woocommerce->order->get_total();
?>
<!-- Google Code for Conversion Page -->
<script>
  gtag('event', 'conversion', {
      'send_to': 'AW-xxxxxxxxxx/abcdefgshig',
      'value': <?php echo $ordertotal; ?>,
      'currency': 'USD',
      'transaction_id': <?php echo $orderid; ?>
  });
</script>
	
<?php } ?>

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And when I place an order just displays a blank page and if I view source it stops at  'value': ,

What am I doing wrong. Any advice is appreciated

Thanks