return response()->download($pathToFile);
return response()->download($pathToFile, $name, $headers);

public function downloadfile($filename)
  {
    $file = public_path().'/test.xls';
    return response()->download($file,$filename.'.xls');
  }

FatalErrorException in HandleCors.php line 18:
Call to undefined method Symfony\Component\HttpFoundation\BinaryFileResponse::header()

class CorsMiddleware
{
  public function handle($request, Closure $next)
  {
    $response = $next($request);
    $response->headers->set('Access-Control-Allow-Origin' , '*');
    $response->headers->set('Access-Control-Allow-Methods', 'POST, GET, OPTIONS, PUT, DELETE');
    $response->headers->set('Access-Control-Allow-Headers', 'Content-Type, Accept, Authorization, X-Requested-With, Application');
    return $response;
  }
}