Command Parameters is null for interactive request from slack

[antony-develop]

I send a message to a user with some buttons.

$botman->say('What do you want to do?', [
    'attachments' => json_encode([
        [
            "fallback" => "Shame... buttons aren't supported in this land",
            "callback_id" => "menu_button",
            "color" => "#3AA3E3",
            "attachment_type" => "default",
            'actions' => [
                [
                    "name" => "study",
                    "text" => "study",
                    "type" => "button",
                    "value" => "study",
                ],
            ]
        ],
        [
            "fallback" => "Shame... buttons aren't supported in this land",
            "callback_id" => "menu_button",
            "color" => "#3AA3E3",
            "attachment_type" => "default",
            'actions' => [
                [
                    "name" => "share_knowledge",
                    "text" => "share_knowledge",
                    "type" => "button",
                    "value" => "share_knowledge",
                ]
            ]
        ],
    ])
]);

And I expect parameter {buttonId} to catch any button value.

**
 * @Route("/interactive", name="botman_interactive")
 */
public function interactive()
{
    $this->botman->hears('{buttonId}', function ($bot, $buttonId) {
        $bot->reply('You click button with id  . $buttonId);
    });

    $this->botman->listen();

    return new Response();
}

But $buttonId var is always null