I am presently trying to use javascript's "fetch" as to get an external file(a gist file, referenced by URL), and I have been able to have it get the intended data and display it within a console log, and have within the function getText() made the array lines work alongside innerHTML, but when i reference the array using window it doesnt seem to work, and the console comes up with an error "Uncaught TypeError: Cannot read properties of undefined (reading '0')" Does anyone have any idea why this might be happening? I think it's local/global variable issues but I'm not wholly sure. Thank you!

   function getText(){
      fetch('myfile.txt')
      .then((res) => res.text())
      .then((data)=> {
        console.log(data);
    
    var lines = [data];

  })
  .catch((err) => {
    console.log(err);
  })
}



var textPosition = 0;
var speed = 100;
typewriter = () => {
  document.querySelector("#type").innerHTML = window.lines[0].substring(0,textPosition) +"<span>\u25ae</span>";

  if(textPosition ++ != window.lines[0].length)
    setTimeout(typewriter,speed);
}
window.addEventListener("load", getText)
window.addEventListener("load", typewriter)