Ошибка MultiValueDictKeyError: django.utils.datastructures.MultiValueDictKeyError: 'td_id_mysite'

С помощью form method = "post" передать значение ячейки на странице html в views.py и далее работать уже с ней там, но выдаёт ошибку. Подскажите, в чём может быть проблема? Заранее спасибо за ответ.

my_newsagent.html

<tbody>
                    {% for element in qz %}
                        <tr>
                            <form action="{% url 'my_newsagent' %}" method = "post">
                                {% csrf_token %}
                                <td class="counterCell"></td>
                                <td style="display: none" name="td_id_mysite">{{ element.0 }}</td>
                                <td>{{ element.1 }}</td>
                                <td>{{ element.2 }}</td>
                                <td><button type="submit"><span class="glyphicon glyphicon-trash"></span></button></td>
                            </form>
                        </tr>
                    {% endfor %}
            </tbody>

views.py

def my_newsagent(request):
cursor = connection.cursor()
cursor1 = connection.cursor()
cursor2 = connection.cursor()
cursor.execute(
    "SELECT sites.site_title, sites.url FROM sites, my_sites, auth_user WHERE auth_user.id = my_sites.id_user AND sites.id = my_sites.id_site AND auth_user.id =" + str(
        request.user.id))
cursor1.execute(
    "SELECT sites.site_title, sites.url FROM sites, my_sites, auth_user WHERE auth_user.id = my_sites.id_user AND sites.id = my_sites.id_site AND auth_user.id =" + str(
        request.user.id))
cursor2.execute(
    "SELECT sites.id, sites.site_title, sites.url FROM sites, my_sites, auth_user WHERE auth_user.id = my_sites.id_user AND sites.id = my_sites.id_site AND auth_user.id =" + str(
        request.user.id))

q = [str(row[0]) for row in cursor.fetchall()]

z = [str(row[1]) for row in cursor1.fetchall()]

x = [str(row[0]) for row in cursor2.fetchall()]

qz = [(x[i], q[i], z[i]) for i in range(len(q))]


if request.method == 'POST':
    print('some text', request.POST)
    td_id_mysite=request.POST["td_id_mysite"]

    print("xxxx")
    print(td_id_mysite)


return render(request, 'main/my_newsagent.html', {'qz': qz})

urls.py

urlpatterns = [
...
path('main/my_news_agent/', views.my_newsagent, name='my_newsagent'),

]

Ошибка: django.utils.datastructures.MultiValueDictKeyError: 'td_id_mysite'