Magento – When we add custom form field in Shipping Address form in Magento2 checkout page,it doesnot reflect in frontend

I am using Magento 2.2.3.

I tried "How to add new Shipping address form field in Checkout Page".Below is my code.

Vendor/Theme/registration.php

<?php
\Magento\Framework\Component\ComponentRegistrar::register(
    \Magento\Framework\Component\ComponentRegistrar::MODULE,
    'Atlantis_Everest',
    __DIR__
);

Vendor/Theme/etc/di.xml

<?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\Onepage">
        <arguments>
            <argument name="layoutProcessors" xsi:type="array">
                <item name="rewrite-checkout-fields" xsi:type="object">Atlantis\Everest\Model\Checkout\LayoutProcessorPlugin</item>
            </argument>
        </arguments>
</type>
</config>

Vendor/Theme/etc/extension_attributes.xml

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Api/etc/extension_attributes.xsd">
    <extension_attributes for="Magento\Quote\Api\Data\AddressInterface">
        <attribute code="custom_field" type="string" />
    </extension_attributes>
</config>

Vendor/Theme/etc/module.xml

<?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="Atlantis_Everest" setup_version="1.0.0" />
</config>

Vendor/Theme/Model/Checkout/LayoutProcessorPlugin.php

<?php
$customAttributeCode = 'custom_field';
$customField = [
    'component' => 'Magento_Ui/js/form/element/abstract',
    'config' => [
        // customScope is used to group elements within a single form (e.g. they can be validated separately)
        'customScope' => 'shippingAddress.custom_attributes',
        'customEntry' => null,
        'template' => 'ui/form/field',
        'elementTmpl' => 'ui/form/element/input',
        'tooltip' => [
            'description' => 'this is what the field is for',
        ],
    ],
    'dataScope' => 'shippingAddress.custom_attributes' . '.' . $customAttributeCode,
    'label' => 'Custom Attribute',
    'provider' => 'checkoutProvider',
    'sortOrder' => 0,
    'validation' => [
       'required-entry' => true
    ],
    'options' => [],
    'filterBy' => null,
    'customEntry' => null,
    'visible' => true,
];

$jsLayout['components']['checkout']['children']['steps']['children']['shipping-step']['children']['shippingAddress']['children']['shipping-address-fieldset']['children'][$customAttributeCode] = $customField;

Vendor/Theme/view/frontend/requirejs-config.js

var config = {
    config: {
        mixins: {
            'Magento_Checkout/js/action/set-shipping-information': {
                'Atlantis_Everest/js/action/set-shipping-information-mixin': true
            }
        }
    }
};

Vendor/Theme/view/frontend/web/js/action/set-shipping-information-mixin.js

/*jshint browser:true jquery:true*/
/*global alert*/
define([
    'jquery',
    'mage/utils/wrapper',
    'Magento_Checkout/js/model/quote'
], function ($, wrapper, quote) {
    'use strict';

    return function (setShippingInformationAction) {

        return wrapper.wrap(setShippingInformationAction, function (originalAction) {
            var shippingAddress = quote.shippingAddress();
            if (shippingAddress['extension_attributes'] === undefined) {
                shippingAddress['extension_attributes'] = {};
            }

            shippingAddress['extension_attributes']['custom_field'] = shippingAddress.customAttributes['custom_field'];
            // pass execution to original action ('Magento_Checkout/js/action/set-shipping-information')
            return originalAction();
        });
    };
});

I did not know how to perform Step 5 mentioned in the link.I performed till Step4. But When I deployed it,it does not show in Frontend. Please help me out. Thanks in advance.