Recuperar un pk en los formularios

def get_form_kwargs(self):

views.py


class CodeVerificationView(FormView):
    template_name = 'users/verification.html'
    form_class = VerificationForm
    success_url = reverse_lazy('users_app:user-login')

    def get_form_kwargs(self):
        kwargs = super(CodeVerificationView, self).get_form_kwargs()
        kwargs.update({
            'pk': self.kwargs['pk'],
        })
        return kwargs

    def form_valid(self, form):
        #
        User.objects.filter(
            id=self.kwargs['pk']
        ).update(
            is_active=True
        )
        return super(CodeVerificationView, self).form_valid(form)

forms.py

def __init__(self, pk, *args, **kwargs):


class VerificationForm(forms.Form):
    codregistro = forms.CharField(required=True)


    def __init__(self, pk, *args, **kwargs):
        self.id_user = pk
        super(VerificationForm, self).__init__(*args, **kwargs)

    def clean_codregistro(self):
        codigo = self.cleaned_data['codregistro']

        if len(codigo) == 6:
            # verificamos si el codigo y el id de usuario son validos:
            activo = User.objects.cod_validation(
                self.id_user,
                codigo
            )
            if not activo:
                raise forms.ValidationError('el codigo es incorrecto')
        else:
            raise forms.ValidationError('el codigo es incorrecto')

urls.py

    path(
        'user-verification/<pk>/', 
        views.CodeVerificationView.as_view(),
        name='user-verification',
    ),