Download not working using filetransfer plugin

i used IonicNative plugin for downloading pdf files

I can see download complete using alert,but cannot see any download happening.

private filetransfer: FileTransferObject = this.transfer.create(); 
  const url = '';, this.file.dataDirectory + 'example%20test.pdf').then((entry) =>
                  alert('download complete: ' + entry.toURL());
 (error) => {

is this the correct way to do or am I missing some thing?