Just 20 lines of code.

Python:

from flask import Flask, request
import requests
import json

app = Flask('app')

@app.route('/<token>', methods=['POST'])
def handle_tg(token):
update = request.get_json()
message=update.get('message')
if message:
send_message_params = {
'chat_id':message['chat']['id'],
'text':json.dumps(message, indent=4),
'reply_to_message_id':message['message_id']
}
r = requests.post(
url=f'https://api.telegram.org/bot{token}/sendMessage',
json=send_message_params
)
return 'OK'

app.run(host='0.0.0.0', port=8080)

---------------------------------------------------------

PHP (Credits: @spechide):

<?php
$token = $_REQUEST["token"];
$content = file_get_contents('php://input'); $update = json_decode($content, true);
if (isset($update["message"])) {
$chat_id = $update["message"]["chat"]["id"];
file_get_contents("https://api.telegram.org/bot$token/sendMessage?chat_id=$chat_id&text=$content");
}