Unable to add tracking script in complete.tpl page

[Omkark]

On complete.tpl page in {if $ispaid} conditions I am trying to implement following code even after using {literal} the variables are not getting correctly.  And what is exact variable for email of customer?

My code 

{if $ispaid}
        <!-- Enter any HTML code which should be displayed when a user has completed checkout here -->
        <!-- Common uses of this include conversion and affiliate tracking scripts -->

<script>
fbq('track', 'Purchase', {currency: "INR", value: '{literal}{$amount}{/literal}'});
</script>
      
<script>
  var enhanced_conversion_data = {
    "email": '{literal}{$clientsdetails.email}{/literal}'  
  }; 
</script>

{literal}
<!-- Global site tag (gtag.js) - Google Ads: 96###### -->
<script async src="https://www.googletagmanager.com/gtag/js?id=AW-96#####0"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config','AW-9#####0', {'allow_enhanced_conversions':true});
</script>
{/literal}

      <script>
        gtag('event', 'conversion', {
        'send_to': 'AW-96#####0/tYVjC#####I68oD',
        'value': '{literal}{$amount}{/literal}',
        'currency': 'INR',
        });
     </script>

        {/if}