<form action="" method="post">
    <input type="text" name="message">
    <input type="submit" name="submit">
</form>


<?php
    if(isset($_POST['submit']))
      {

     $botToken="7151616173:AAF8dxMtekbZU9glo4h7cKSDEO7iP-mD6mE";

  $website="https://api.telegram.org/bot".$botToken;
  $chatId="5214868552";
  $params=[
      'chat_id'=>$chatId, 
      'text'=>$message,
  ];
$response = file_get_contents("https://api.telegram.org/bot$apiToken/sendMessage?" . http_build_query($data) );    
    }
?>