Untitled

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <button id="btnRecord">download</button>
  <script type="text/javascript">
    const inputFile = document.querySelector('#inputFile');

    btnRecord.addEventListener('click', function(e) {
      const blob = new Blob(['this is just a test'], {
        type: 'text/plain'
      });
      const url = URL.createObjectURL(blob);
      const a = document.createElement('a');
      a.style.display = 'none';
      a.href = url;
      a.download = 'test.txt';
      document.body.append(a);
      a.click();
      setTimeout(function() {
        document.body.removeChild(a);
        URL.revokeObjectURL(url);
      }, 0);
    });
  </script>
</body>
</html>