magento-test/app/code/Magento/Checkout/Test/Mftf/ActionGroup/FillGuestCheckoutShippingAddressFormActionGroup.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
 /**
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
-->

<actionGroups xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/actionGroupSchema.xsd">
    <actionGroup name="FillGuestCheckoutShippingAddressFormActionGroup">
        <arguments>
            <argument name="customer" defaultValue="Simple_US_Customer" type="entity"/>
            <argument name="customerAddress" defaultValue="US_Address_TX" type="entity"/>
        </arguments>
        <fillField selector="{{CheckoutShippingSection.emailAddress}}" userInput="{{customer.email}}" stepKey="setCustomerEmail"/>
        <fillField selector="{{CheckoutShippingSection.firstName}}" userInput="{{customer.firstname}}" stepKey="SetCustomerFirstName"/>
        <fillField selector="{{CheckoutShippingSection.lastName}}" userInput="{{customer.lastname}}" stepKey="SetCustomerLastName"/>
        <fillField selector="{{CheckoutShippingSection.street}}" userInput="{{customerAddress.street[0]}}" stepKey="SetCustomerStreetAddress"/>
        <fillField selector="{{CheckoutShippingSection.city}}" userInput="{{customerAddress.city}}" stepKey="SetCustomerCity"/>
        <fillField selector="{{CheckoutShippingSection.postcode}}" userInput="{{customerAddress.postcode}}" stepKey="SetCustomerZipCode"/>
        <fillField selector="{{CheckoutShippingSection.telephone}}" userInput="{{customerAddress.telephone}}" stepKey="SetCustomerPhoneNumber"/>
    </actionGroup>
</actionGroups>