const utmParameterKeys = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_content'];
 
function addUTMParametersToLinks() {
  const urlSearchParams = new URLSearchParams(window.location.search);
  const linkElements = document.querySelectorAll('a[href]');
 
  // クエリパラメータがない場合は処理を終了
  if (!Array.from(urlSearchParams).length) return;
 
  for (const linkElement of linkElements) {
    if (!linkElement.href) continue;
 
    const linkElementURL = new URL(linkElement.href);
    const parametersToAdd = [];
 
    for (const parameterKey of utmParameterKeys) {
      const currentPageParamValue = urlSearchParams.get(parameterKey);
      const linkElementParamValue = linkElementURL.searchParams.get(parameterKey);
 
      // リンクに同じUTMパラメータがない場合のみ追加
      if (currentPageParamValue && !linkElementParamValue) {
        parametersToAdd.push(`${parameterKey}=${currentPageParamValue}`);
      }
    }
 
    if (parametersToAdd.length > 0) {
      const queryConnector = linkElementURL.search ? '&' : '?';
      linkElement.href += queryConnector + parametersToAdd.join('&');
    }
  }
}
 
addUTMParametersToLinks();

リンクにUTMパラメータを結合するためのScriptです。

UTM sync

var LIFF_SDK_ASSETS_URL = "https://static.line-scdn.net/liff/edge"
var LIFF_SDK_VERSION = "2.25.1"
  
var liffSrc = `${LIFF_SDK_ASSETS_URL}/versions/${LIFF_SDK_VERSION}/sdk.js`;
var liffScript = document.createElement("script");
  
liffScript.setAttribute("src", liffSrc);
liffScript.setAttribute("type", "text/javascript");
  
liffScript.onload = function () {
  const LIFF_ID = "1592258037-kDyx2ABV"; // chirashi-real
  liff.init({
    liffId: LIFF_ID
  }).then(() => console.log('complete liff.init()'))
};
  
document.head.appendChild(liffScript);