Джанго Брейнтри Интеграция

Question

Я хотел бы интегрировать платеж Braintree на свой веб-сайт.Я знаю, что в моем коде много ошибок, так как я учусь.В настоящее время я перенаправлен на страницу Failed http, так как платеж не проходит.Как я могу осуществить платеж на странице корзины?Спасибо.

views.py (приложение корзины)

    def cart_detail(request, total=0, cart_items = None):
        try:
            cart = Cart.objects.get(cart_id=_cart_id(request))
            cart_items = CartItem.objects.filter(cart=cart, active=True)
            for cart_item in cart_items:
                total += (cart_item.service.price)
        except ObjectDoesNotExist:
            pass


        gateway = braintree.BraintreeGateway(
            braintree.Configuration(
                braintree.Environment.Sandbox,
                merchant_id="",
                public_key="",
                private_key=""
            )
        )

        braintree_total = int(total)
        #print(braintree_total)

        if request.method == 'GET':

            client_token = gateway.client_token.generate()

        else: # for when the method is POST
            print(request.POST)

            result = gateway.transaction.sale({
                'amount': braintree_total, 
                'payment_method_nonce': request.POST['payment_method_nonce'],
                'options': {
                    "submit_for_settlement": True
                }
            })

            if result.is_success or result.transaction:
                return HttpResponse('Done')

            return HttpResponse('Failed')

        return render(request, 'cart.html', dict(cart_items = cart_items, total = total, client_token = client_token))

cart.html (приложение корзины)

            <div class="col-12 col-sm-12 col-md-12 col-lg-6 text-center">
                <table class="table my_custom_table">
                    <thead class="my_custom_thead">
                        <tr>
                            <th>
                                Checkout
                            </th>
                        </tr>
                    </thead>
                    <tbody>
                        <tr>
                            <td>
                                Please review your shopping cart items before proceeding with the order payment.
                            </td>
                        </tr>
                        <tr>
                            <td class="text-left">
                                Your total is: <strong>£{{ total }}</strong>
                            </td>
                        </tr>
                    </tbody>
                </table>
                <div class="mx-auto">
                    <form id="payment-form" method="post" action="{% url 'cart:cart_detail' %}">
                        {% csrf_token %}

                        <div id="bt-dropin"></div>
                        <input type="hidden" id="nonce" name="payment_method_nonce" />
                        <button class="btn btn-primary btn-block" type="submit" id="submit-button"><span>Test Transaction</span></button>
                    </form>

                    <a href="{% url 'home:allProd' %}" class="btn btn-secondary btn-block my_custom_button">Continue Shopping</a>
                </div>
            </div>
        </div>
        <br>


    {% endif %}

<script src="https://js.braintreegateway.com/web/dropin/1.13.0/js/dropin.min.js"></script>
    <script>
        var button = document.querySelector('#submit-button');
        var client_token = '{{ client_token }}';

        braintree.dropin.create({
            authorization: client_token,
            container: '#bt-dropin',
            paypal: {
                flow: 'vault'
            }
        }, function (createErr, instance) {
            form.addEventListener('submit', function (event) {
                event.preventDefault();

                instance.requestPaymentMethod(function (err, payload) {
                    if (err) {
                    console.log('Error', err);
                    return;
                }

                // Add the nonce to the form and submit
                document.querySelector('#nonce').value = payload.nonce;
                form.submit();
                });
            });
        });
    </script>
{% endblock %}

Спасибо за помощь.