<?php
$botToken = '***';
$chatId = '***';
$message = $_POST['message'];

function sendMessage($botToken, $chatId, $message) {
    $url = "https://api.telegram.org/bot" . $botToken . "/sendMessage?chat_id=" . $chatId . "&text=" . urlencode($message);
    $response = file_get_contents($url);
    return $response;
}

$response = sendMessage($botToken, $chatId, $message);
var_dump($response);
?>