<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button id="loadScript">Load Script</button>
<script>
    let scriptLoaded = false;
const loadScriptButton = document.getElementById("loadScript");
loadScriptButton.addEventListener("click", () => {
  if (!scriptLoaded) {
    const script = document.createElement("script");
    script.src = "1.js";
    document.body.appendChild(script);
    scriptLoaded = true;
  }
});
    
</script>

</body>
</html>