magento-test/app/code/Magento/Captcha/Test/Mftf/ActionGroup/StorefrontCheckoutPaymentsWithCaptchaActionGroup.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="StorefrontCheckoutPaymentsWithCaptchaActionGroup">
        <arguments>
            <argument name="captcha" type="string"/>
        </arguments>

        <waitForElementVisible selector="{{StorefrontCaptchaOnOnepageCheckoutPyamentSection.captchaField}}" stepKey="waitForCaptchaField"/>
        <fillField selector="{{StorefrontCaptchaOnOnepageCheckoutPyamentSection.captchaField}}" userInput="{{captcha}}" stepKey="fillCaptchaField"/>
    </actionGroup>
</actionGroups>