gtag based implementation of GA4 dataLayer population

gtag.liquid

<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-5GE0TR6RDZ"></script>
<script>

    let args = {
        'event': "orderconfirmation",
        'discount': '{{ order.total_discounts }}',
        'shippingPrice': '{{ order.shipping_price | money_without_currency | replace: ",", "." }}',
        'transactionTax': '{{ order.tax_price | money_without_currency | replace: ",", "." }}',
        'transactionSubtotal': '{{ order.subtotal_price | money_without_currency | replace: ",", "." }}',
        'transactionTotal': '{{ order.total_price | money_without_currency | replace: ",", "." }}',
        'transactionId': '{{ order.name }}',
        'currency': '{{ shop.currency }}',
        'totalProducts': '{{ order.line_items.size }}',
        'payment_type': '{{ order.transactions[0].gateway }}',
        'products': '[{% for item in order.line_items %}{{ item.product.title }}{% unless forloop.last %},{% endunless %}{% endfor %}]'
    }

    window.dataLayer = window.dataLayer || [];
    function gtag() { window.dataLayer.push(args); }
    gtag('js', new Date());

    gtag('config', 'GA_MEASUREMENT_ID');
</script>