Fatal error: Uncaught Error: Call to a member function add_panel() on null in /home/zadanie333/public_html/zadaniexynl/wypozyczalnia/wp-content/themes/sydney/inc/integrations/lifter/customize.php:9 Stack trace: #0 {main} thrown in /home/zadanie333/public_html/zadaniexynl/wypozyczalnia/wp-content/themes/sydney/inc/integrations/lifter/customize.php on line 9