magento-test/app/code/Magento/Downloadable/Test/Mftf/Page/StorefrontDownloadableSamplePage.xml

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

<pages xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:noNamespaceSchemaLocation="urn:magento:mftf:Page/etc/PageObject.xsd">
    <page name="StorefrontDownloadableSamplePage" url="downloadable/download/sample/sample_id/{{id}}/" area="storefront" module="Magento_Downloadable" parameterized="true">
    </page>
</pages>