Telegram bot inline keyboard via Node.JS

I’m using the node-telegram-bot-api module, How can I make my keyboard to inline Keyboard? This is my code:

bot.onText(/^/start$/, function (msg) {
    const opts = {
        reply_to_message_id: msg.message_id,
        reply_markup: {
            resize_keyboard: true,
            one_time_keyboard: true,
            keyboard: [ ['Level 1'] ]
        }
    };

    bot.sendMessage(msg.chat.id, "I'm a test robot", opts);
});

Answer

I answered a question similar to this link: How can create menu for telegram bot in bot father?

in your case you could use:

keyboard: [["uno :+1:"],["uno ud83dudc4d", "due"],["uno", "due","tre"],["uno", "due","tre","quattro"]]