Orsdxy

I am making a module to insert a custom fields to quote address.

My File

Modulename/etc/frontend/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="MagentoCheckoutBlockCheckoutLayoutProcessor">

        <plugin name="impunkj_add_custom_field" type="ImpunkjCheckoutPluginCheckoutModelCheckoutLayoutProcessor" sortOrder="100"/>

    </type>

</config>

Modulename/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="MagentoQuoteApiDataAddressInterface">

        <attribute code="dropdown" type="string" />

    </extension_attributes>

</config>

Also Layout Processor
ImpunkjCheckoutPluginCheckoutModelCheckout

<?php

namespace ImpunkjCheckoutPluginCheckoutModelCheckout;





class LayoutProcessor

{

    /**

     * @param MagentoCheckoutBlockCheckoutLayoutProcessor $subject

     * @param array $jsLayout

     * @return array

     */

    public function afterProcess(

        MagentoCheckoutBlockCheckoutLayoutProcessor $subject,

        array  $jsLayout

    ) {

    $customAttributeCode = 'dropdown';

    $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;

    return $jsLayout;

    }

}

Also in
Checkout/view/frontend/require-config.js

var config = {

    config: {

        mixins: {

            'Magento_Checkout/js/action/set-shipping-information': {

                'Impunkj_Checkout/js/action/set-shipping-information-mixin': true

            }

        }

    }

};

File
Modulename/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']['dropdown'] = shippingAddress.customAttributes['dropdown'];

            // pass execution to original action ('Magento_Checkout/js/action/set-shipping-information')

            return originalAction();

        });

    };

});

Is there anything is missing
Please if someone can help with this