Sidebar setAttribute isn't working

[Jackson Tong]

add_hook('ClientAreaSecondarySidebar', 1, function($secondarySidebar) {
	$shortcuts = $secondarySidebar->getChild('Client Shortcuts');

	$shortcuts->addChild(
        'Google',
        array(
            'name' => 'Google',
            'label' => 'Google',
            'uri' => 'https://google.com',
            'order' => 10,
            'icon' => 'fa-rocket',
        )
    )
        ->setAttribute('target', '_blank') // working
        ->setAttribute('rel', 'noreferrer'); // not working
});

with this code I can only see target attribute in my a tag.