My widget not printing before_widgets and after widgets

first add this code to functions.php

register_sidebar(array(
        'name' => __('Top Footer', 'educate'),
        'id' => 'top-footer',
        'description' => __('Top Full width footer.', 'educate'),
        'before_widget' => '<div class="footer-widget %2$s" id="%1$s" >',
        'after_widget' => '</div>',
        'before_title' => '<h3 class="footer-widget-title">',
        'after_title' => '</h3>',
    ));

after add this code where you want to show widget

       <?php if (is_active_sidebar('top-footer')) {

        if (is_active_sidebar('top-footer')) {
                        echo '<aside class="col-md-12 col-sm-6">';
                        dynamic_sidebar('top-footer');
                        echo '</aside>';
                    }


        } ?>