如何在结账页将优惠券转移到Magento 2的侧栏？

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="Custom_Checkout" setup_version="1.0.0">
        <sequence>
            <module name="Magento_Checkout"/>
        </sequence>
    </module>
</config>

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <type name="Magento\Checkout\Block\Cart\Sidebar">
        <plugin name="custom_checkout_sidebar" type="Custom\Checkout\Plugin\SidebarPlugin" sortOrder="1"/>
    </type>
</config>

<?php

namespace Custom\Checkout\Plugin;

class SidebarPlugin
{
    public function afterGetDefaultItems(\Magento\Checkout\Block\Cart\Sidebar $subject, $result)
    {
        $couponCode = $subject->getQuote()->getCouponCode();
        if ($couponCode) {
            $couponItem = [
                'code' => $couponCode,
                'title' => __('Coupon'),
                'value' => '-' . $subject->getQuote()->getBaseCurrency()->formatTxt($subject->getQuote()->getDiscountAmount()),
            ];
            array_push($result, $couponItem);
        }
        return $result;
    }
}

php bin/magento module:enable Custom_Checkout
php bin/magento setup:upgrade
php bin/magento cache:clean