Stream() is not working, gets downloaded automatically

Question

Actually I am trying to stream pdf file in browser by using laravel snappy pdf. But it gets download all time.

$pdf = \PDF::loadView('sale::print-pos', [
    'sale' => $sale,
])
    ->setPaper('a7')
    ->setOption('margin-top', 8)
    ->setOption('margin-bottom', 8)
    ->setOption('margin-left', 5)
    ->setOption('margin-right', 5);

return $pdf->stream('sale-'. $sale->reference .'.pdf');