I want to add a custom field in Shipping Zone page under shipping method, it will be a text input, the user will able to add a custom message and I'll show that message in the front end.
I noticed it saves the data in wp_woocommerce_shipping_zone_methods table which doesn't have any extra column to save the data; so I think I have to use my custom logic, but I don't know the name of the hook(s).
So my question is, is there is any hook which will help/allow me
- To add a custom field.
- To add a custom column.

