function pageHasPcScript(){
  if(document.documentElement.innerHTML.includes('sdk.pop-convert.com/sdk.js')) return true;
  if(document.querySelector('script[src*="sdk.pop-convert.com/sdk.js"]')) return true;
  return false;
}

if(pageHasPcScript()){
  console.log('Pop Convert script found')
} else {
  const script = document.createElement('script')
  script.id = 'ck-pc-embed-script'
  var shop = (window.Shopify && window.Shopify.shop) || (window.myPC && window.myPC.unique_id) || '';
  script.setAttribute('src','https://sdk.pop-convert.com/sdk.js' + (shop ? '?shop=' + encodeURIComponent(shop) : ''));
  script.async = true
  document.head.appendChild(script)
}