def METHOD_NAME(self, request: HttpRequest, form: Form, form_url: str):
    login_url = reverse(self.init_url, request=request)
    auth_return_url = reverse(
        "authentication:return",
        kwargs={"slug": form.slug, "plugin_id": self.identifier},
    )
    return_url = furl(auth_return_url).set(
        {
            "next": form_url,
        }
    )
    if co_sign_param := request.GET.get(CO_SIGN_PARAMETER):
        return_url.args[CO_SIGN_PARAMETER] = co_sign_param
    redirect_url = furl(login_url).set({"next": str(return_url)})
    return HttpResponseRedirect(str(redirect_url))