<?php
$botToken = '***';
$chatId = '***';
$message = $_POST['message'] ?? 'Hello, World!';

if (!function_exists('sendMessage')) {
    function sendMessage($botToken, $chatId, $message) {
        $query = http_build_query([
            'chat_id' => $chatId,
            'text' => $message
        ]);
        $url = "https://api.telegram.org/bot{$botToken}/sendMessage?{$query}";
        $ch = curl_init();
        $optArray = [
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CUSTOMREQUEST => 'GET',
            CURLOPT_SSL_VERIFYPEER => false,
            CURLOPT_SSL_VERIFYHOST => false
        ];
        curl_setopt_array($ch, $optArray);
        $result = curl_exec($ch);
        if (curl_errno($ch)) {
            $result = curl_error($ch);
        }
        curl_close($ch);
        return $result;
    }
}

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