keyboard_markup = types.ReplyKeyboardMarkup(resize_keyboard=True, row_width=3)
bt1 = types.KeyboardButton(text = "Кнопка1")
bt2 = types.KeyboardButton(text = "Кнопка2")
keyboard_markup.add(bt1,bt2)
@dp.message_handler(commands=['start',])
async def send_start(message: types.Message):
await message.answer("Привет. Держи меню:",reply_markup=keyboard_markup)