Conditionally make Postcode Checkout Field required except for specific country in WooCommerce

Question

I want to make a WooCommerce Postcode Checkout Field that only required when the country is not saudi Arabia . This field should only be required when the customer chose a country other then saudi arabia

But it doesn't work

function woocommerce_no_postcode(array $fields): array
{
  // bail if the country is not SA
  if (!isset($_POST['billing_country']) || 'SA' === $_POST['billing_country']) {
    return $fields;
  }
  $fields['billing']['postcode']['required'] = true;
  return $fields;
}
add_filter('woocommerce_checkout_fields', 'woocommerce_no_postcode', 10, 1);');

Answer 1

The following will do the job, making WooCommerce postcode Checkout Field required only when the country is not Saudi Arabia:

add_filter( 'woocommerce_get_country_locale', 'custom_country_locale_postcode', 10, 1 );
function custom_country_locale_postcode( $locale ) {
    foreach ( $locale as $country => $data ){
        $locale[$country] = array( 'postcode' => array(
            'required' => true,
        ) );
    }

    $locale['SA'] = array( 'postcode' => array(
        'required' => false,
    ) );

    return $locale;
}

Code goes in functions.php file of your child theme (or in a plugin). Tested and works.