How to send message to channel user without user interaction

Based on discussion in this thread: https://github.com/akalongman/php-telegram-bot/issues/71#issuecomment-183177739

To send message to user/channel without initiating message from user (usually, for broadcasting message), you can use the following snippet:

<?php
$loader = require __DIR__.'/vendor/autoload.php';
use Longman\TelegramBot\Request;
$API_KEY = '--botfather-api-keu--';
$BOT_NAME = '--bofather-bot-name--';
$telegram = new Longman\TelegramBot\Telegram($API_KEY, $BOT_NAME);
$message = isset($argv[2]) ? $argv[2] : '';
$telegramId = isset($argv[1]) ? $argv[1] : '';
if($message !== '' && $telegramId !== ''){
  $data = [];
  $data['chat_id'] = $telegramId;
  $data['text'] = $message;
  $result = Request::sendMessage($data);
  if ($result->isOk()) {
      echo 'Message sent succesfully to: '.$data['chat_id'] ;
  } else {
      echo 'Sorry message not sent to: '.$data['chat_id'] ;
  }
}
//to use it, just call: $php broadcast.php [telegram-chat-id] [message]