i can't add bootstrap carousel in my wordpress query

<div class="container post-items">
      <div id="demo" class="carousel slide" data-bs-ride="carousel">
          <div class="post-item carousel-inner">
              <ul class="blog carousel-item ">
                  <?php
                  $args = array(
                      'post_type'      => 'post',
                      'posts_per_page' => '4',
                      'cat'         => '3',
                      'orderby'        => 'modified'

                  );
                  ?>
                  <?php
                  $query = new WP_Query($args);
                  while ($query->have_posts()) {

                      $query->the_post(); ?>


                      <li class="blog-grid d-block card" style="width:100%">
                          <a href="<?php the_permalink() ?>"><?php the_title() ?></a>
                          <a href="<?php the_permalink() ?>"><?php the_post_thumbnail('medium') ?></a>
                      </li>



                  <?php } ?>
              </ul>

          </div>
      </div>
  </div>

i want to show my blog post in carousel way,and i use bootstrap classes in my loop query.but it's not working and doesn't show any thing.could some one help me findout why?