download.js

download: function () {
  let csvContent = "data:text/csv;charset=utf-8,";
  csvContent += document.getElementById("bulktextarea").value;

  var encodedUri = encodeURI(csvContent);
  var link = document.createElement("a");
  link.setAttribute("href", encodedUri);
  link.setAttribute("download", "BitcoinKeys.csv");
  document.body.appendChild(link);

  link.click();
},