Sometime you want to update the checkout total based on a specific field. e.g how to update WooCommerce checkout total with postcode field.
Enter the value in billing_postcode field and as you blur. The jQuery( ‘body’ ).trigger( ‘update_checkout’ ); will be triggered and the checkout total will be updated.
Use the following code snippet within theme functions.php
Custom WooCommerce Plugin Development
WooCommerce Auto Update Cart When Quantity Changes
WooCommerce Checkout Page Fields
Checkout Field Editor