Возникает ошибка в коде для отправки рассылки через форму на сайте, в чем дело?

<?php
$link = mysqli_connect($config_db["host"], $config_db["user"], $config_db["password"], $config_db["database"]);
if (!$link) {
    echo "Errore di connessione." . PHP_EOL;
    exit;
 
}
 
$sql = "SELECT email FROM user WHERE subscribed = 1";
$result = mysqli_query($link,$sql);
while($subscribed_db = mysqli_fetch_all($result, MYSQLI_ASSOC)); 
 
<?php
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;
use PHPMailer\PHPMailer\Exception;
 
require_once "vendor/autoload.php";
 
$mail = new PHPMailer(true);
 
//Enable SMTP debugging.
$mail->SMTPDebug = 3;
//Set PHPMailer to use SMTP.
$mail->isSMTP();
//Set SMTP host name
$mail->Host = "smtp.gmail.com";
//Set this to true if SMTP host requires authentication to send email
$mail->SMTPAuth = true;
 
//If SMTP requires TLS encryption then set it
$mail->SMTPSecure = "tls";
//Set TCP port to connect to
$mail->Port = 587;
//CharSet
$mail->CharSet = 'UTF-8';
 
//Provide username and password
$mail->Username = "veronikasam7@gmail.com";
$mail->Password = "veronikasam";
//From
$mail->setFrom('veronikasam7@gmail.com');
$mail->FromName = "Veronika Sam";
//Reply
$mail->addReplyTo("veronikasam7@gmail.com", "Reply");
foreach($subscribed_db as $news_mail){ //
        $mail->addBCC($news_mail.";");
    }
$mail->Subject = "name";
$mail->Body = "<i> formnews </i>";
 
//Send HTML or Plain Text
$mail->isHTML(true);
 
 
 
 
try {
⠀⠀⠀⠀$mail->send();                                                               // ТУТ ОШИБКА
⠀⠀⠀⠀echo "Message has been sent successfully";
} catch (Exception $e) {
⠀⠀⠀⠀echo "Mailer Error: " . $mail->ErrorInfo;
}
?>

<form action="news.php" method="post" class="reg_form">
     <div class="row">
<div class="col-md-6">
                    <img src="./../assets/img/miele.png" alt="Sweet Honey" class="img-fluid">
</div>
    <div class="col-md-6">
    <header class="section-header">
                <h1 class="mb-4"> Newsletter </h1>
        </header>
        </div>
                              
<form name="news" method="POST" action="news.php">
  <label> Заголовок:   </br> <input type="text" name="name"  ></label></br></br>
          Сообщение:<br> 
        <textarea name='message_text' cols='60' rows='5'></textarea><br><br> 
        <input type='submit' name='button' id='button' value='Отправить'> 
        </form>  
 
</form>

$result = mysqli_query($link,'SELECT u.email FROM user WHERE up.subscribed = 1');
$array = array();
$mail = null;
while ($row = mysqli_fetch_assoc($result))
{
    $array[] = $row['email'];
}
foreach($array as $news_mail){ 
    $mail->addBCC($news_mail.";"); 
}

$mail = null;

$mail->addBCC($news_mail.";");

$mail->addBCC($news_mail);