Pourquoi je vois ce message d'erreur pour mon chatbot

 <?php
// Connection data (server_address, database, name, poassword)
$hostdb = 'localhost';
$namedb = 'intell693_Basedonnees';
$userdb = 'intell693_databa';
$passdb = 'Ferrari20';


 // Connect and create the PDO object
 $db = new PDO("mysql:host=$hostdb; dbname=$namedb", $userdb, $passdb);
 $messenger_id = $_GET['messenger_user_id'];
$stmt = $db->prepare("select * from users where messenger_id = $messenger_id");
$stmt->execute();
$myarr=array();
while($data=$stmt->fetch()){
   $myarr[]=$data;
   
}

   
 // echo json_encode($myarr);
  
  $file = fopen('data.json' ,'w');
  fwrite($file, json_encode($myarr, JSON_FORCE_OBJECT));
  
  $url = 'data.json'; // path to your JSON file
$data = file_get_contents($url); // put the contents of the file into a variable
$characters = json_decode($data); // decode the JSON feed

//echo $characters[0]->first_name;
//echo $characters[0]->last_name;
//echo $characters[0]->email_address;
//echo json_encode($data);




 // Define and perform the SQL SELECT query
 //$messenger_id = $_GET['messenger_user_id'];
 //$sql = "SELECT * FROM `users` WHERE `messenger_id` = $messenger_id";
 //$result = $conn->query($sql);
 










?>