I am uploading HTML file in blob container, but file not created,Can anyone help here.

var formData = new FormData();
var fileBlob = new Blob([mystring], { type: "text/html"});
formData.append('filename', 'test.html');
formData.append('file', fileBlob);
blobServicedev.createBlockBlobFromText(
  'adshaltraceurl',
  'test.html',
  JSON.stringify(formData),
  option,
  function(error, result, response) {
    if (error) {
      console.log(error);
    } else {
      console.log('blob uploaded successfully');
    }
  }
);