Add GTM purchase tracking on my Shopify store

Job ID: 36395593

Budget: €8 – €30 EUR

Hi, on shopify its difficult to add a Google Tag manager script to the header of thank you page , to register a purchase.
If you an expert and you can do it direclty ( i want also see what you doing on it with shared screen)
then i choose you.

the script example:
header:

<!-- Google Tag Manager -->
<script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','GTM-xxxxxx');</script>
<!-- End Google Tag Manager -->
Related categories: PHP JavaScript HTML Shopify Templates Shopify