How to make inline buttons with a url correctly?

Question

@bot.message_handler(commands=['group'])
def add_to_group(message):
    markup = types.InlineKeyboardMarkup()
    markup.add(types.InlineKeyboardButton(text='Add the bot to your group', url='http://t.me/botusername?startgroup=botstart'))
    bot.send_message(message.chat.id, 'Add me to your chat', reply_markup=markup)

I made this code and when the /group command is inputed it gives out text with an inline button, but the button is light gray and isn't clickable at all!

I expected a clickable inline button that will take me to the choose chat menu.