<h2 class="accordion-header">
  <button class="accordion-button collapsed" type="button" data-bs-toggle="collapse"
    data-bs-target="#flush-heading-Board" aria-expanded="false"
    aria-controls="flush-heading-Board"><b>사이트관리</b></button>
</h2>
<div id="flush-heading-Board" class="accordion-collapse collapse show" aria-labelledby="flush-heading-Board">
  <div class="accordion-item">
    <h2><a href="/admin/board">게시글 관리</a></h2>
  </div>
  <div class="accordion-item">
    <h2><a href="/admin/sitepage">SitePage 관리</a></h2>
  </div>
</div>