For a custom field in your plugin, as $this->order seems to be the instance of the WC_Order object, you will try to use $this->order->get_id() to ...
WooCommerce Codex - Checkout Field Hook
i need to edit this field value in admin side . Currently i can edit all other values in billing address but this value is not appearing in admin section . I use the ...
'_wc_acof_{id}', true ) to get the value of that custom field for a particular order.
How to Customize WooCommerce Checkout Fields
You can add multiple shipping methods within this zone.
Do you find yourself putting a lot of information in your “Order Notes” or using
This will ensure that our custom field value is displayed on the order ...
If you are wondering how to add custom field in WooCommerce checkout page, ... customise (add, edit, delete and change display order) your fields displayed on ... In edit form you have the option to provide new values for Name, Type, Label, ...
Sort Order; Field Width. Show fields on checkout under account section: If you have enabled registrations during the checkout, ...