// Initialize PHP Auth library $auth = new \Delight\Auth\Auth($db); // Check if user is authenticated if ($auth->isLoggedIn()) { // Retrieve username of authenticated user $username = $auth->getUsername(); // Display username on webpage echo "Welcome, " . $username . "!"; // Write username to log file $log = fopen("logfile.txt","a"); fwrite($log, "User " . $username . " accessed this page on " . date("Y-m-d H:i:s") . "\n"); fclose($log); }The PHP Auth library is a package that provides simple authentication and authorization features for PHP projects.