如何打开只有选中评论的回复文本框？

<!-- HTML -->
<div class="comment">
  <p>This is a comment.</p>
  <button class="reply-btn">Reply</button>
  <textarea class="reply-textbox" style="display: none;"></textarea>
</div>

<!-- JavaScript -->
<script>
  // 获取所有的评论回复按钮
  const replyButtons = document.getElementsByClassName("reply-btn");

  // 遍历每个回复按钮并添加点击事件监听器
  for (let i = 0; i < replyButtons.length; i++) {
    replyButtons[i].addEventListener("click", function() {
      // 找到相应的回复文本框
      const comment = this.parentElement;
      const replyTextbox = comment.getElementsByClassName("reply-textbox")[0];

      // 显示回复文本框
      replyTextbox.style.display = "block";
    });
  }
</script>