Пользовательский метод доставки с дополнительной проблемой выбора поля в блоке WooCommerce Checkout

Я написал плагин WooCommerce для добавления точек обслуживания SF Express на страницу блокировки оформления заказа. Раскрывающийся список отображается правильно, но выбранная опция не передается в PHP, поэтому примечания к заказу не отражают выбранную точку обслуживания. Ниже приведены соответствующие фрагменты моего кода PHP и JS. Я попытался зарегистрировать данные POST, и кажется, что выбранный параметр неправильно передается функции PHP. Любые идеи или предложения о том, что может быть не так?

PHP-код:

<?php
if (!defined('ABSPATH')) {
    exit;
}

if (in_array('woocommerce/woocommerce.php', apply_filters('active_plugins', get_option('active_plugins')))) {
    function sf_express_shipping_method_init() {
        if (!class_exists('WC_Shipping_SF_Express')) {
            class WC_Shipping_SF_Express extends WC_Shipping_Method {
                public function __construct() {
                    $this->id = 'sf_express';
                    $this->method_title = __('SF Express Service Points', 'sf_express');
                    $this->method_description = __('Allows customers to pick up parcels from SF Express Service Points.', 'sf_express');
                    $this->init();
                }

                function init() {
                    $this->init_form_fields();
                    $this->init_settings();
                    $this->enabled = $this->get_option('enabled');
                    $this->title = $this->get_option('title');
                    add_action('woocommerce_update_options_shipping_' . $this->id, array($this, 'process_admin_options'));
                }

                function init_form_fields() {
                    $this->form_fields = array(
                        'enabled' => array(
                            'title' => __('Enable/Disable', 'sf_express'),
                            'type' => 'checkbox',
                            'label' => __('Enable SF Express Service Points', 'sf_express'),
                            'default' => 'yes'
                        ),
                        'title' => array(
                            'title' => __('Title', 'sf_express'),
                            'type' => 'text',
                            'description' => __('This controls the title which the user sees during checkout.', 'sf_express'),
                            'default' => __('SF Express Service Points', 'sf_express'),
                            'desc_tip' => true,
                        ),
                        'service_points_csv' => array(
                            'title' => __('Service Points CSV', 'sf_express'),
                            'type' => 'textarea',
                            'description' => __('Paste the contents of your service points CSV file here.', 'sf_express'),
                            'default' => '',
                        ),
                    );
                }

                public function calculate_shipping($package = array()) {
                    $rate = array(
                        'id' => $this->id,
                        'label' => $this->title,
                        'cost' => '0',
                        'calc_tax' => 'per_order'
                    );
                    $this->add_rate($rate);
                }
            }
        }
    }

    add_action('woocommerce_shipping_init', 'sf_express_shipping_method_init');
    add_filter('woocommerce_shipping_methods', function($methods) {
        $methods['sf_express'] = 'WC_Shipping_SF_Express';
        return $methods;
    });

    add_action('wp_enqueue_scripts', function() {
        wp_enqueue_script('sf_express', plugins_url('/sf-express.js', __FILE__), array('jquery'), '1.0', true);
        wp_localize_script('sf_express', 'sf_express_params', array(
            'ajax_url' => admin_url('admin-ajax.php')
        ));
    });

    // AJAX Handler for fetching service points
    add_action('wp_ajax_fetch_sf_express_service_points', 'fetch_sf_express_service_points');
    add_action('wp_ajax_nopriv_fetch_sf_express_service_points', 'fetch_sf_express_service_points');

    function fetch_sf_express_service_points() {
        $options = get_option('woocommerce_sf_express_settings');
        $csv_data = $options['service_points_csv'];
        $lines = explode("\n", $csv_data);
        $html = '';
        foreach ($lines as $line) {
            $parts = explode(',', trim($line));
            if (count($parts) >= 2) {
                $html .= '<option value = "' . esc_attr(trim($parts[0])) . '">' . esc_html(trim($parts[1])) . '</option>';
            }
        }
        echo $html;
        wp_die();
    }

    add_action('woocommerce_checkout_create_order', function($order, $data) {
        // Log the posted service point value
        error_log('Selected SF Express Service Point: ' . print_r($_POST['sf_express_service_point'], true));

        if (!empty($_POST['sf_express_service_point'])) {
            $service_point = sanitize_text_field($_POST['sf_express_service_point']);
            $order->update_meta_data('sf_express_service_point', $service_point);
            $note = 'SF Express Service Point: ' . $service_point;
            $order->add_order_note($note);
        }
    }, 10, 2);

    function debugging( $order_id ) {
        $order = wc_get_order( $order_id );

        // Log the POST data for debugging
        error_log('POST Data: ' . print_r($_POST, true));

        if (isset($_POST['sf_express_service_point']) && !empty($_POST['sf_express_service_point'])) {
            $service_point = sanitize_text_field($_POST['sf_express_service_point']);
            error_log('Service Point: ' . $service_point); // Debug logging
            $order->update_meta_data('sf_express_service_point', $service_point);
            $note = 'Testing: ' . $service_point;
            $order->add_order_note($note);
            $order->save();
        } else {
            $note = 'Testing: Service point not set';
            $order->add_order_note($note);
            $order->save();
        }
    }
    add_action('woocommerce_thankyou', 'debugging', 10, 1);


    add_action('woocommerce_checkout_process', function() {
        if (empty($_POST['sf_express_service_point']) && isset($_POST['shipping_method'][0]) && $_POST['shipping_method'][0] === 'sf_express') {
            wc_add_notice(__('Please select an SF Express Service Point.', 'sf_express'), 'error');
        }
    });

    add_action('woocommerce_admin_order_data_after_billing_address', function($order) {
        $service_point = $order->get_meta('sf_express_service_point');
        if ($service_point) {
            echo '<p><strong>' . __('SF Express Service Point', 'sf_express') . ':</strong> ' . esc_html($service_point) . '</p>';
        }
    });

    add_filter('woocommerce_email_order_meta_fields', function($fields, $sent_to_admin, $order) {
        $service_point = $order->get_meta('sf_express_service_point');
        if ($service_point) {
            $fields['sf_express_service_point'] = array(
                'label' => __('SF Express Service Point', 'sf_express'),
                'value' => esc_html($service_point),
            );
        }
        return $fields;
    }, 10, 3);

    add_action('woocommerce_order_details_after_order_table', function($order) {
        $service_point = $order->get_meta('sf_express_service_point');
        if ($service_point) {
            echo '<p><strong>' . __('SF Express Service Point', 'sf_express') . ':</strong> ' . esc_html($service_point) . '</p>';
        }
    });
}

JS-код:

jQuery(document).ready(function($) {
    console.info('SF Express script loaded');

    function addServicePointField() {
        console.info('Checking if service point field needs to be added');
        if ($('#sf_express_service_point').length === 0) {
            console.info('Adding service point field');
            var servicePointFieldHtml = '<div class = "form-row form-row-wide">' +
                '<label for = "sf_express_service_point">' +
                'SF Express Service Point' +
                '</label>' +
                '<select id = "sf_express_service_point" name = "sf_express_service_point" class = "select">' +
                '<option value = "">Select a service point</option>' +
                '</select>' +
                '</div>';

            // Append to the shipping method container
            $('.wc-block-components-shipping-rates-control__package').append(servicePointFieldHtml);
            updateServicePointField(); // Fetch and update the dropdown
        }
    }

    function removeServicePointField() {
        console.info('Removing service point field if it exists');
        $('#sf_express_service_point').parent().remove();
    }

    function updateServicePointField() {
        console.info('Fetching updated service points');
        $.ajax({
            url: sf_express_params.ajax_url,
            type: 'POST',
            data: {
                action: 'fetch_sf_express_service_points'
            },
            success: function(response) {
                console.info('Service points fetched successfully');
                $('#sf_express_service_point').html(response);
            }
        });
    }

    // Initial call with a delay to ensure all dynamic elements are rendered
    setTimeout(addServicePointField, 1000);

    // Re-add the service point field when the shipping method changes
    $(document).on('change', 'input[name = "shipping_method[0]"]', function() {
        var shippingMethod = $(this).val();
        if (shippingMethod === 'sf_express') {
            addServicePointField();
        } else {
            removeServicePointField();
        }
    });

    // Ensure the field is included in the form submission
    $('form.checkout').on('checkout_place_order', function() {
        var servicePoint = $('#sf_express_service_point').val();
        console.info('Selected service point: ' + servicePoint); // Debugging
        if (servicePoint) {
            $('<input>').attr({
                type: 'hidden',
                name: 'sf_express_service_point',
                value: servicePoint
            }).appendTo('form.checkout');
        } else {
            console.info('No service point selected');
        }
    });

    // Trigger the addServicePointField function when the page loads and shipping method is already selected
    if ($('input[name = "shipping_method[0]"]:checked').val() === 'sf_express') {
        addServicePointField();
    }
});

Селектор точек обслуживания отображается, но выбранная опция не сохраняется вместе с заказом. Я попытался зарегистрировать данные POST, и кажется, что выбранная опция не передается функции PHP правильно. Любые идеи или предложения о том, что может быть не так?