In mftf, popup elements are not getting identified

Question

In Test folder

        xsi:noNamespaceSchemaLocation="../../../../../../vendor/magento/magento2-functional-testing-framework/src/Magento/FunctionalTestingFramework/Test/etc/testSchema.xsd">
<test name="PlaceOrderSuccessfullyPageTest">
    <annotations>
        <features value="Place order successfully"/>
        <stories value="Place order"/>
        <title value="Buy Giftcard "/>
        <description value="Buy giftcard"/>
        <severity value="CRITICAL"/>
        <testCaseId value="MAGETWO-25589"/>
        <group value="place_order_successfully"/>
    </annotations>
    <after>         
        <amOnPage url="admin/admin/auth/logout/" stepKey="amOnLogoutPage"/>
    </after>
    <amOnPage url="personal-gift-cards.html" stepKey="amOnHomePage"/>
    <waitForPageLoad stepKey="waitForPageLoad1"/>
    <moveMouseOver selector="{{StorefrontCategoryMainSection.ProductItemInfo}}" stepKey="hoverProduct"/>
    <click selector="{{PlaceOrderSuccessfullyPageSection.selectProduct}}" stepKey="selectProduct"/>     
    <waitForAjaxLoad stepKey="ajaxLoad1"/>
    <seeInPopup userInput="Gold Sparkle" stepKey="seeProductName"/>
    <fillField selector="#qty" userInput="10" stepKey="enterQty"/>     
</test>
</tests>

I am getting error i.e  Field by name, label, CSS or XPath element with '#qty' was not found.