您可以使用script.onload JavaScript来加载带有回调的脚本。
在这里，您可以单独访问JS加载。

试试下面的代码

function addScript(url, id, callback) {
    // Check if the script has already been added
  if (!document.getElementById(id)) {
      // Create a script element for the script
    var script = document.createElement('script');
    script.src = url;
    script.id = id;

      // Add the onload event handler
    script.onload = function() {
        // Call the callback function when the script has finished loading
      if (typeof callback === 'function') {
        callback();
      }
    };

      // Add the script element to the head section of the page
    document.head.appendChild(script);
  }
}

console.log("initiate");
document.addEventListener("readystatechange", (event) => {
  if (event.target.readyState === "interactive") {
    console.log("Page ready");

    addScript(
      "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js",
      "jquery-script",
      function () {
        console.log("jquery loaded");
      }
    );
  }
});