尝试在django中添加任何评论时，添加评论表单显示错误

def add_comment(request):
    if request.method == 'POST':
        form = CommentForm(request.POST)
        if form.is_valid():
            # 处理有效的表单数据
            comment = form.save(commit=False)
            comment.user = request.user
            comment.save()
            return redirect('comments:list')
    else:
        form = CommentForm()
    
    return render(request, 'add_comment.html', {'form': form})

<form method="post">
  {% csrf_token %}
  {{ form.as_p }}
  {% if form.errors %}
    <div class="alert alert-danger">
      <strong>错误：</strong>
      {% for field_errors in form.errors.values %}
        {% for error in field_errors %}
          {{ error }}
        {% endfor %}
      {% endfor %}
    </div>
  {% endif %}
  <button type="submit">提交评论</button>
</form>