guacamole-client/extensions/guacamole-auth-duo/src/main/resources/templates/duoSignedResponseField.html

<div class="duo-signature-response-field-container">
    <div class="duo-signature-response-field" ng-class="{ loading : !duoInterfaceLoaded }">
        <iframe></iframe>
        <input type="submit">
    </div>
</div>