How to Add a Custom Country State/Region to WooCommerce | WordPress
How to adding a custom state/region in the shipping options for woocommerce. How to disable the proceed to checkout button if no shipping options are available.
Add Waiheke Island, New Zealand to WooCommerce shipping options
1st code snippet: https://pastebin.com/bS91p25A
2nd code snippet: https://pastebin.com/f8TwRQZY
North Island zip/postcodes: https://pastebin.com/nmN3Aimz