magento-test/app/code/Magento/Paypal/Test/Mftf/ActionGroup/StorefrontPayPalPaymentActionGroup.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="LoginToPayPalPaymentAccount">
        <arguments>
            <argument name="credentials" defaultValue="_CREDS"/>
        </arguments>
        <fillField selector="{{PayPalPaymentSection.email}}" userInput="{{credentials.magento/paypal_sandbox_login_email}}" stepKey="fillEmail"/>
        <click selector="{{PayPalPaymentSection.nextButton}}" stepKey="clickNext"/>
        <waitForElementVisible selector="{{PayPalPaymentSection.password}}" stepKey="waitForPasswordField"/>
        <fillField selector="{{PayPalPaymentSection.password}}" userInput="{{credentials.magento/paypal_sandbox_login_password}}" stepKey="fillPassword"/>
        <click selector="{{PayPalPaymentSection.loginBtn}}" stepKey="clickLogin"/>
        <waitForPageLoad stepKey="waitForLoginPageLoad"/>
        <click selector="{{PayPalPaymentSection.continueButton}}" stepKey="clickContinue"/>
    </actionGroup>
</actionGroups>