need to add a java function in the last page prestashop 1.7

[spc]

Im going to change my question of this topic.
And i hope someone is understand what i mean.

I need to add a java function to the checkout page and thank you page, i have search the internet but i can´t find witch page it is.
So i hope someone can point me in the right direction.

The java function i need to add to the page is :

{literal}
<script>
pertentoReportConversion('purchase', {
  currencyCode: order.currency,     
  revenue: order.totalAmount,       
  tax: order.taxAmount,             
  shipping: order.shippingCost      
})
</script>
{/literal}

Where can i find the transaction page.

I use prestashop 1.7.6.0

Edited July 30 by spc
Change my question (see edit history)

[Knowband Plugins]

Adding changes directly to the files is not suggested. Use hooks like displayHeader OR displayFooter from the custom module to achieve the same.

Also, I believe you are adding the JS changes. If yes, then they can be added in the header.tpl OR fotter.tpl of the theme file. 

Path for the default theme 

themes/classic/templates/_partials/header.tpl
themes/classic/templates/_partials/footer.tpl

 

 

 

[spc]

Hi, thanks for your answer, could you show an example of how to get this code into the script.
I honestly don't know how I'm supposed to put it in.