This code is the simplest code in the internet that can communicate with the telegram bot

<?php
 if(!preg_match('/^149\.154\.167\.(19[7-9]|20[0-9]|21[0-9]|22[0-9]|23[0-3])$/', $_SERVER['REMOTE_ADDR'])) {
 die('IP Address not allowed.');
 }
 if($_SERVER['REQUEST_METHOD'] != 'POST') {
 die('Request method not allowed.');
 }
 $token = '<bot token here>';
 $rcv = file_get_contents('php://input');
 $m = json_decode($rcv, true);
 
 print_r($m);
 if(isset($m['message']['text'])) {
 $chatid = $m['message']['chat']['id'];
 $firstname = $m['message']['chat']['first_name'];
 sendmsg($m, 'Hi '.$firstname.'!');
 }
 function sendmsg($m, $msg) {
 global $token;
 $chatid = $m['message']['chat']['id'];
 $firstname = $m['message']['chat']['first_name'];
 unset($a); exec('curl -s -d "chat_id='.$chatid.'&text='.urlencode($msg).'" "https://api.telegram.org/bot'.$token.'/sendMessage"', $a);
 }
?>