Javascript : call back , calling function on demand from code

 function callback(arg) {

  console.log(arg);

  alert(arg);

}

const loadscript = (src, callback) => {

  let sc = document.createElement("script");

  sc.src = src;

  sc.onload = callback("Pulkit");

  document.head, append(sc);

};

loadscript(

  "https://cdnjs.cloudflare.com/ajax/libs/prism/9000.0.1/prism.min.js",

  callback

);