<?php

$uniqueid = "";
$username = "";

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception as PHPMailerException;
require dirname(__FILE__) . '/phpmailer/src/Exception.php';
require dirname(__FILE__) . '/phpmailer/src/PHPMailer.php';
require dirname(__FILE__) . '/phpmailer/src/SMTP.php';

$db = mysqli_connect('localhost', 'root', '', 'occupation');

if (!$db) {
die("Connection failed: " . mysqli_connect_error());
}

$email=$_GET['email'];
//***********here query in the data base but not valid if it exists********************
$sql ="SELECT uniqueid, username FROM users WHERE email='$email'";

if (isset($_GET['email'])) {

$message = "Salut! Bienvenue au site. \nvotre ID est : '$uniqueid'\n"
. "votre nom d'utilisateur est : '$username'";

$subject = 'Merci';

// ========== SEND EMAIL TO USER ======================
$mail = new PHPMailer(true);
$smtp_credentials = [
'username' => 'email@gmail.com', // change to your gmail address
'password' => 'password' // change to your gmail password
];
try {
$mail->isSMTP();
$mail->isHTML(true);
$mail->SMTPDebug = 0;
$mail->SMTPAuth = true;
$mail->Username = $smtp_credentials['username'];
$mail->Password = $smtp_credentials['password'];
$mail->SMTPSecure = 'tls';
$mail->Host = 'smtp.gmail.com';
$mail->Port = 587;
$mail->SMTPOptions = array(
'ssl' => array(
'verify_peer' => false,
'verify_peer_name' => false,
'allow_self_signed' => true
)
);
// email context
$mail->setFrom($smtp_credentials['username'], 'Mohamed Douhaji');
//*********************here you will leave in username because you have not received data from database**************************
$mail->addAddress($email, $username);
$mail->Subject = $subject;
$mail->Body = $message;
$mail->AltBody = strip_tags($message);

// send email
$mail->send();
} catch (PHPMailerException $e) {
die('Message could not be sent. ' . $mail->ErrorInfo);
}

}

?>