Почему не применяется widgets к форме?

Question

[Викентий]

# forms.py
class UserLoginForm(AuthenticationForm):
    class Meta:
        model = User
        fields = ['username', 'password']

        widgets = {
            "username": TextInput({
                "placeholder": "Введите Email адрес",
                "class": "form-control",
            }),
            "password": PasswordInput({
                "placeholder": "Введите свой пароль",
                "class": "form-control",
            }),
        }

# views.py
def sign_in(request):
    form = UserLoginForm()
    data = {
        "form": form
    }
    return render(request, "main/pages/sign_in.html", data)

<form method="post" class="flex_form">
    {% csrf_token %}
    {{ form.username }}
    <br>
    {{ form.password }}
    <br>
    <button type="submit">Авторизоваться</button>
</form>

Форма есть, но widgets к ней не применился:
Результат на странице:

<form method="post" class="flex_form">
    <input type="hidden" name="csrfmiddlewaretoken" value="gZaaiaacfGEh0N3O4Vsts8wcmyga9nJsrKlesQ54zANDa4bsahNwJasGDAo14sCl">
    <input type="text" name="username" autofocus="" autocapitalize="none" autocomplete="username" maxlength="150" required="" id="id_username">
    <br>
    <input type="password" name="password" autocomplete="current-password" required="" id="id_password">
    <br>
    <button type="submit">Авторизоваться</button>
</form>