magento-test/app/code/Magento/Sales/Test/Mftf/ActionGroup/AdminSalesOrderCommentsActionGroup.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="AdminSalesOrderCommentsActionGroup">
        <annotations>
            <description>Adding comments on admin sales order details page</description>
        </annotations>
        <arguments>
            <argument name="comment" type="string" defaultValue=""/>
        </arguments>
        <fillField selector="{{AdminSalesOrderCommentsSection.historyComment}}" userInput="{{comment}}" stepKey="fillComment"/>
        <checkOption selector="{{AdminSalesOrderCommentsSection.historyVisible}}" stepKey="checkVisibleOnStoreFront"/>
        <click selector="{{AdminSalesOrderCommentsSection.submitOrderComment}}" stepKey="clickSaveCommentButton"/>
        <waitForPageLoad stepKey="waitForSaveComments"/>
    </actionGroup>
</actionGroups>