<form method='POST'>
    Username: <input type='text' name='user' id='user'><br>
    Password: <input type='password' name='passwd' id ='passwd'><br>
  <input type='submit'>
  </form>

  <?php
    include_once 'connection.php';
    $username = mysqli_real_escape_string($conn, $_POST['user']);
    $password = 'passwd';
    $hash = 'SELECT passwd FROM users WHERE username = $username ';


if (password_verify($password, $hash)) {
        // valid, proceed to login
        $_SESSION['loggedin'] = true;
        header( 'Location: session.php' );
        exit;
    }