Afficher un PopUp à la fin d'un chargement

<?php
include('pdo.php');



        require 'mailjet/vendor/autoload.php';
        use \Mailjet\Resources;

    $stmt = $pdo->prepare('SELECT * FROM statusEmails where status in ("sent","queued")');
    
	$stmt->execute();
    $status = $stmt->fetchAll();

    foreach($status as $res)
    {

        $id = $res['messageId'];
        

        $mj = new \Mailjet\Client('bce86e9943d59ded740db2a28c2f3083', 'a1db2837eee29a897454015828aba390');
        $response = $mj->get(Resources::$Message, ['id' => $id]);
        $response->success();
        foreach($response->getData() as $res2)
        {
            $dateT = str_replace('T',' ',$res2['ArrivedAt']);
            $date = str_replace('Z','',$dateT);
            $status = $res2['Status']; 
        }
       

               $stmt = $pdo->prepare("UPDATE statusEmails SET status = :status, date = :date  WHERE id = :id");
               $stmt->bindValue(':id', (int)$res["id"], PDO::PARAM_INT);
               $stmt->bindValue(':status', $status, PDO::PARAM_STR);
               $stmt->bindValue(':date', $date, PDO::PARAM_STR);
               $stmt->execute();
               $stmt->closeCursor();

               $table = $res['categorie'];

               if($table == 'clients')
               {
                   //pour avoir les coordonnées du client
                    $stmt = $pdo->prepare('SELECT * FROM clients WHERE dernierMailjetId = :dernierMailjetId');
                    $stmt->bindValue(':dernierMailjetId', $id, PDO::PARAM_STR);
                    $stmt->execute();
                    $client = $stmt->fetch();
                    
                    
                    if(!empty($client))
                    {
                        var_dump('mail1');
                    
                        $stmt = $pdo->prepare("UPDATE $table SET dernierStatus = :dernierStatus WHERE id = :id");
                        $stmt->bindValue(':id', (int)$res["idCat"], PDO::PARAM_INT);
                        $stmt->bindValue(':dernierStatus', $status, PDO::PARAM_STR);
                        $stmt->execute();
                        $stmt->closeCursor();
                    }
                    else {
                        
                        $stmt = $pdo->prepare("UPDATE $table SET dernierStatus2 = :dernierStatus WHERE id = :id");
                        $stmt->bindValue(':id', (int)$res["idCat"], PDO::PARAM_INT);
                        $stmt->bindValue(':dernierStatus', $status, PDO::PARAM_STR);
                        $stmt->execute();
                        $stmt->closeCursor();
                        
                    }
                    

               }
               else {
              
               $stmt = $pdo->prepare("UPDATE $table SET dernierStatus = :dernierStatus WHERE id = :id");
               $stmt->bindValue(':id', (int)$res["idCat"], PDO::PARAM_INT);
               $stmt->bindValue(':dernierStatus', $status, PDO::PARAM_STR);
               $stmt->execute();
               $stmt->closeCursor();
                    
                
            }




    }


    header('Location:'.$_SERVER['HTTP_REFERER']);
     ?>