Insert subtotal value inside scripts on viewinvoice.tpl

[vam87t]

Hello,

I have this scripts inside the literal tag, into file viewinvoice.tpl

{literal}
<!-- Meta Pixel Code -->
<script>
[...]
fbq('init', 'XXXXXXXXXXX');
fbq('track', 'PageView');
fbq('track', 'Purchase', {value: {/literal}1{literal}, currency: 'EUR'});
</script>

I need to populate the part of "{value: {/literal}1{literal}, currency: 'EUR'});" with the variable {$subtotal}

How can I insert the valut of the subtotal of the invoice, inside the "{value: SUBTOTAL_IMPORT, currency: 'EUR'}" ?

Anyone can help me?

Best Regards