I can’t get markup of any site using a bot

there is a bot that in the greeting requests the url of the site from which it will pull the html markup

but when entering the URL throws an exception I would like to note that in the conditional construction! = "": it should be so, because the bot has not been done yet and I send only the url

import requests


token = "????"

bot = telebot.TeleBot(token)

@bot.message_handler(commands=["start"])
def start_messgin(message):
    bot.send_message(message.chat.id, "Добро пожаловать, {0.first_name}!\nЯ - <b>{1.first_name}</b>, бот парсер!Чтобы начать отправь ссылку на сайт".format(message.from_user, bot.get_me()),
        parse_mode="html")

@bot.message_handler(content_types=["text"])
def mes(message):
    if message.chat.type == "private":
        if message.text != "":
            res = requests.get(message.text).text
            bot.send_message(message.chat.id, res)

bot.polling(none_stop=True)

Ошибка:
 ERROR - TeleBot: "A request to the Telegram API was unsuccessful. The server returned HTTP 400 Bad Request. Response body:
[b'{"ok":false,"error_code":400,"description":"Bad Request: message is too long"}']"