Make Billing Phone required on Checkout Field Based on Shipping Method - Woocommerce - php

Question

I want to set the billing phone number required or not required based on the shipping method.
I have set the shipping method as an array and checked it from the session selected shipping method but it not working
add_filter('woocommerce_checkout_fields', 'fire_remove_billing_checkout_fields');
function fire_remove_billing_checkout_fields($fields) {
global $woocommerce;
$methods = array('flat_rate:2', 'flat_rate:3', 'flat_rate:17', 'flat_rate:20');// Set shipping method to hide the checkout field(s).
$chosen_methods = WC()->session->get( 'chosen_shipping_methods' );
$chosen_shipping = $chosen_methods[0];
if(in_array($chosen_shipping, $methods)){
$fields['billing']['billing_phone'][ 'required' ] = true;
}else{
$fields['billing']['billing_phone'][ 'required' ] = false;
}
return $fields;
}

Answer 1

Your code works well for me. I've added my shipping rate IDs and it works as expected, however refresh of the page is necessary, because WooCommerce doesn't refresh the billing fields natively on update_checkout trigger.
You should either reload the page using Javascript/jQuery on updated_checkout event, or reload only the billing fields using AJAX like so:
add_action( 'wp_footer', 'reload_billing_fields_on_updated_checkout' );
function reload_billing_fields_on_updated_checkout() {
?>
<script>
jQuery(document.body).on('updated_checkout', () => {
jQuery('.woocommerce-billing-fields').load(`${location.href} .woocommerce-billing-fields>*`, '');
});
</script>
<?php
}
Keep in mind that it might take a short while for those fields to reload, so you might want to add some loading CSS classes, or maybe a spinner.