Warning: require_once(db.class.php): Failed to open stream: No such file or directory in /var/www/html/clases/producto.class.php on line 2

Fatal error: Uncaught Error: Failed opening required 'db.class.php' (include_path='.:/usr/share/php') in /var/www/html/clases/producto.class.php:2 Stack trace: #0 /var/www/html/clases/carrito.class.php(3): require_once() #1 /var/www/html/ingresar.php(6): require_once('...') #2 {main} thrown in /var/www/html/clases/producto.class.php on line 2