Shopify (theme.liquid)

In Online Store → Themes → Edit code, open layout/theme.liquid and add before </head>:

<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('consent', 'default', {
    ad_storage: 'denied',
    ad_user_data: 'denied',
    ad_personalization: 'denied',
    analytics_storage: 'denied'
  });
</script>
<div id="cmp-root"></div>
<!-- Load your CMP bundle here (e.g., from your CDN) and mount to #cmp-root -->