WooCommerce将自定义字段数据发布到“订单详细信息”页面问题

我在第一个WooCommerce自定义领域非常接近 . 我的问题似乎是将自定义字段的输入数据发布到“订单详细信息”页面上 .

对于我的生活，我似乎无法找到这个代码的问题：

// Register main datepicker jQuery plugin script
            add_action( 'wp_enqueue_scripts', 'enabling_date_picker' );
            function enabling_date_picker() {

                // Only on front-end and checkout page
                if( is_admin() || ! is_checkout() ) return;

                // Load the datepicker jQuery-ui plugin script
                wp_enqueue_script( 'jquery-ui-datepicker' );
            }

            // Call datepicker functionality in your custom text field
            add_action('woocommerce_after_order_notes', 'my_custom_checkout_field', 10, 1);
            function my_custom_checkout_field( $checkout ) {

                date_default_timezone_set('America/Los_Angeles');
                $mydateoptions = array('' => __('Select PickupDate', 'woocommerce' ));

                echo '<div id="my_custom_checkout_field">
                <h3>'.__('Empty Cylinder Collection').'</h3>';

                // YOUR SCRIPT HERE BELOW 
                echo '
                <script>
                    jQuery(function($){
                        $("#datepicker").datepicker();
                    });
                </script>';

               woocommerce_form_field( 'cylinder_collect_date', array(
                    'type'          => 'text',
                    'class'         => array('my-field-class form-row-wide'),
                    'id'            => 'datepicker',
                    'required'      => false,
                    'label'         => __('Collection Date'),
                    'placeholder'       => __('Select Date'),
                    'options'     =>   $mydateoptions
                    ),$checkout->get_value( 'cylinder_collect_date' ));

                echo '</div>';
            }
            /**
             * Process the checkout
             **/
            add_action('woocommerce_checkout_process', 'my_custom_checkout_field_process');

            function my_custom_checkout_field_process() {
                global $woocommerce;

                // Check if set, if its not set add an error.
                if (!$_POST['cylinder_collect_date'])
                     wc_add_notice( '<strong>Collection Date</strong> ' . __( 'is a required field.', 'woocommerce' ), 'error' );
            }

             /**
             * Update the order meta with custom fields values
             * */
             add_action('woocommerce_checkout_update_order_meta', 'my_custom_checkout_field_update_order_meta');

             function my_custom_checkout_field_update_order_meta($order_id) {

            if (!empty($_POST['cylinder_collect_date'])) {
                update_post_meta($order_id, 'Pick-up Empty Cylinder', sanitize_text_field($_POST['cylinder_collect_date']));
            }
            }

            /**
             * Display Custom Shipping fields and custom fields in custom area in the Order details area in Woocommerce->orders
             *  */
            add_action('woocommerce_admin_order_data_after_shipping_address', 'my_custom_fields_display_admin_order_meta', 10, 1);

            function my_custom_fields_display_admin_order_meta($order) {
            echo "<h4>Empty Cylinder Collection</h4>";
            echo '<p><strong>' . __('Collection Date') . ':</strong><br> ' . get_post_meta($order->id, 'cylinder_collect_date', true) . '</p>';

             }

             /**
             * Display Custom Billing fields in the Order details area in Woocommerce->orders
              * */
             add_action('woocommerce_admin_order_data_after_billing_address', 'my_custom_billing_fields_display_admin_order_meta', 10, 1);

            function my_custom_billing_fields_display_admin_order_meta($order) {
            echo "<h4>Empty Cylinder Collection</h4>";
            echo '<p><strong>' . __('Collection Date') . ':</strong><br> ' . get_post_meta($order->id, 'cylinder_collect_date', true) . '</p>';
             }

我正在使用Flatsome主题，我将此代码添加到主题的inc文件中

参考：https://stage.helium2go.com.au

任何帮助将不胜感激