@webtoffee when I try to add the above code, I got the following error when I try to generate the shipping labels:
Fatal error: Uncaught ArgumentCountError: Too few arguments to function wt_pklist_add_custom_css_in_shippinglabel(), 2 passed in /home/ernal266/public_html/tokomasmulia.com/wp-includes/class-wp-hook.php on line 287 and exactly 3 expected in /home/ernal266/public_html/tokomasmulia.com/wp-content/plugins/mulia-additional-codes/mulia-additional-codes.php:111 Stack trace: #0 /home/ernal266/public_html/tokomasmulia.com/wp-includes/class-wp-hook.php(287): wt_pklist_add_custom_css_in_shippinglabel(”, ‘shippinglabel’) #1 /home/ernal266/public_html/tokomasmulia.com/wp-includes/plugin.php(206): WP_Hook->apply_filters(”, Array) #2 /home/ernal266/public_html/tokomasmulia.com/wp-content/plugins/print-invoices-packing-slip-labels-for-woocommerce/admin/modules/customizer/customizer.php(347): apply_filters(‘wf_pklist_add_c…’, ”, ‘shippinglabel’) #3 /home/ernal266/public_html/tokomasmulia.com/wp-content/plugins/print-invoices-packing-slip-labels-for-woocommerce/admin/modules/customizer/customizer.php(772): Wf_Woocommerce_Packing_List in /home/ernal266/public_html/tokomasmulia.com/wp-content/plugins/mulia-additional-codes/mulia-additional-codes.php on line 111
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