thank you for reading my message. I am working on a website, but whenever I want to display a number from a database field on the website, no errors, but nothing is shown.
(sorry for bad english)
auth
session_start();
if(!isset($_SESSION["username"])) {
    header("Location: login.php");
    exit();
}
login
  require('db.php');
session_start();
// When form submitted, check and create user session.
if (isset($_POST['username'])) {
    $username = stripslashes($_REQUEST['username']);    // removes backslashes
    $username = mysqli_real_escape_string($con, $username);
    $password = stripslashes($_REQUEST['password']);
    $password = mysqli_real_escape_string($con, $password);
    // Check user is exist in the database
    $query    = "SELECT * FROM `users` WHERE username='$username'
                 AND password='" . md5($password) . "'";
    $result = mysqli_query($con, $query) or die(mysql_error());
    $rows = mysqli_num_rows($result);
    if ($rows == 1) {
        $_SESSION['username'] = $username;
        $_SESSION['coins'] = $coins;
        // Redirect to user dashboard page
        header("Location: dashboard-2.php");
    } else {
        echo "<div class='form'>
              <h3>Je wachtwoord of gebruikersnaam is onjuist.</h3><br/>
              <p class='link'>Klik hier om <a href='login.php'>terug</a> te gaan.</p>
              </div>";
    }
} else {
coins need to be shown on the dashboard.
 
     
    