如何在bootstrap下拉列表中定位插入符号

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.min.css">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js"></script>

<div class="dropdown">
  <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdownMenuButton" data-bs-toggle="dropdown" aria-expanded="false">
    下拉列表
  </button>
  <ul class="dropdown-menu" aria-labelledby="dropdownMenuButton">
    <li><a class="dropdown-item" href="#">选项1</a></li>
    <li><a class="dropdown-item" href="#">选项2</a></li>
    <li><a class="dropdown-item" href="#">选项3</a></li>
  </ul>
</div>

var dropdownMenu = document.querySelector('.dropdown-menu');
dropdownMenu.addEventListener('click', function(event) {
  var target = event.target;
  var dropdownToggle = dropdownMenu.parentElement.querySelector('.dropdown-toggle');
  dropdownToggle.innerHTML = target.innerHTML + ' <span class="caret"></span>';
});