Fatal error: Uncaught Error: Call to undefined function is_ajax_request() in /var/www/html/otomatikkapisatis/controllers/FavoritesController.php:46 Stack trace: #0 /var/www/html/otomatikkapisatis/routes.php(189): FavoritesController->add() #1 /var/www/html/otomatikkapisatis/index.php(37): Router->route() #2 {main} thrown in /var/www/html/otomatikkapisatis/controllers/FavoritesController.php on line 46