Error:

wc_add_notice( sprintf( __( 'You can only have 1 %s in your cart.', 'woocommerce' ), $_product->get_name() ), 'error' );

Success:

wc_add_notice( sprintf( __( 'Kasutajat %s pole registreeritud. Loo kasutaja', 'orkla-theme' ), $_SESSION['login_username'] ?? '' ), 'success' );

Info:

wc_add_notice( 'This is a general notice.', 'notice' );

Hoiatus:

wc_add_notice( 'This is a warning message.', 'warning' );