How to Hide Tikex Payment and Invoice Integration Admin Menus

function plt_hide_tiket_payment_invoicing_menus() {
	//Hide the "Tikex" menu.
	remove_menu_page('tiket-hu');
	//Hide the "Settings → WP Reactivate" menu.
	remove_submenu_page('options-general.php', 'tiket-on-wordpress');
}

add_action('admin_menu', 'plt_hide_tiket_payment_invoicing_menus', 11);

Where do I put this code?