function loadScript(url, callback) { 
  const element = document.createElement("script"); 
  element.type = "text/javascript"; 
  element.src = url; 
  element.onload = callback; 
  document.body.appendChild(element); 
}

loadScript("js/common.js", () => {
loadScript("<https://cdn.jsdelivr.net/npm/[email protected]/build/global/luxon.min.js>",
() => {
console.log("timer.js ")
})
})