24Degrees

 <div id="main-slider" class="carousel slide mt-4" data-ride="carousel">

             <?php $args = array(
                'posts_per_page' => 5,
                'tag' => 'slider'
             );
             $slider = new WP_Query($args);
             if($slider->have_posts()):
             $count = $slider->found_posts;
             ?>