您应该在问题中给予所有必要的相关代码。请记住 “问题寻求调试帮助（“为什么这段代码不工作？“）必须包括所需的行为、特定的问题或错误以及在问题本身中重现它所需的最短代码"。
因此，在下面的代码中，您将找到一个完整的工作解决方案，具有额外的自定义单选按钮，它将根据所选单选按钮和“本地拾取”运输方法动态添加送货费用。

代码 （您需要在其中定义目标“本地拾取”方法ID）：

// Enabling delivery options for a specific defined shipping method
function targeted_shipping_method(){
    // HERE below define the shipping method Id that enable the custom delivery options
    return 'local_pickup:5';
}

// Customizing Woocommerce checkout radio form field
add_action( 'woocommerce_form_field_radio', 'custom_form_field_radio', 20, 4 );
function custom_form_field_radio( $field, $key, $args, $value ) {
    if ( ! empty( $args['options'] ) && is_checkout() ) {
        $field = str_replace( '</label><input ', '</label><br><input ', $field );
        $field = str_replace( '<label ', '<label style="display:inline;margin-left:8px;" ', $field );
    }
    return $field;
}

// Add a custom radio fields for packaging selection
add_action( 'woocommerce_review_order_after_shipping', 'checkout_shipping_form_delivery_addition', 20 );
function checkout_shipping_form_delivery_addition(){
    $domain = 'wocommerce';

    if (  WC()->session->get( 'chosen_shipping_methods' )[0] == targeted_shipping_method() ) :

        echo '<tr class="delivery-radio"><th>' . __('Delivery options', $domain) . '</th><td>';

        $chosen = WC()->session->get('chosen_delivery');
        $chosen = empty($chosen) ? WC()->checkout->get_value('delivery') : $chosen;
        $chosen = empty($chosen) ? 'regular' : $chosen;

        // Add a custom checkbox field
        woocommerce_form_field( 'radio_delivery', array(
            'type' => 'radio',
            'class' => array( 'form-row-wide' ),
            'options' => array(
                'regular' => __('Regular', $domain),
                'premium' => __('Premium +'.wc_price(2.00), $domain),
            ),
            'default' => $chosen,
        ), $chosen );

        echo '</td></tr>';

    endif;
}

// jQuery - Ajax script
add_action( 'wp_footer', 'checkout_delivery_script' );
function checkout_delivery_script() {
    // Only checkout page
    if ( ! is_checkout() ) return;
    ?>
    <script type="text/javascript">
    jQuery( function($){
        if (typeof wc_checkout_params === 'undefined')
            return false;

        $('form.checkout').on('change', 'input[name=radio_delivery]', function(e){
            e.preventDefault();
            var d = $(this).val();
            $.ajax({
                type: 'POST',
                url: wc_checkout_params.ajax_url,
                data: {
                    'action': 'delivery',
                    'delivery': d,
                },
                success: function (result) {
                    $('body').trigger('update_checkout');
                    console.log(result); // just for testing | TO BE REMOVED
                },
                error: function(error){
                    console.log(error); // just for testing | TO BE REMOVED
                }
            });
        });
    });
    </script>
    <?php

}

// Get Ajax request and saving to WC session
add_action( 'wp_ajax_delivery', 'wc_get_delivery_ajax_data' );
add_action( 'wp_ajax_nopriv_delivery', 'wc_get_delivery_ajax_data' );
function wc_get_delivery_ajax_data() {
    if ( isset($_POST['delivery']) ){
        $delivery = sanitize_key( $_POST['delivery'] );
        WC()->session->set('chosen_delivery', $delivery );
        echo json_encode( $delivery ); // Return the value to jQuery
    }
    die();
}

// Add a custom dynamic delivery fee
add_action( 'woocommerce_cart_calculate_fees', 'add_packaging_fee', 20, 1 );
function add_packaging_fee( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // Only for targeted shipping method
    if (  WC()->session->get( 'chosen_shipping_methods' )[0] != targeted_shipping_method() )
        return;

    if( WC()->session->get( 'chosen_delivery' ) == 'premium' )
        $cart->add_fee( __( 'Delivery fee', 'woocommerce' ), 2.00 );
}

代码放在活动子主题（或活动主题）的functions.php文件中。测试和作品。