No User matches the given query

I am creating a page which lets a user edits his or her name, in which the model was built on top of the AbstractUser class in Django. However, Django raised a 404 error No User matches the given query:

views.py

@method_decorator(login_required, name='dispatch')
class ChangeInfoView(generic.edit.UpdateView):
    model = models.User
    template_name = 'myaccount/change_name.html'
    form_class = forms.UpdateNameForm

    def get_object(self):
        return get_object_or_404(models.User, slug=models.User.slug)

    def get_success_url(self):
        return reverse('profile', kwargs={'slug': self.object.slug})

models.py

class User(util_models.CreationModificationDateMixin, util_models.UrlMixin, AbstractUser):
    slug = models.SlugField(unique=True)
    avatar = models.ImageField('Avatar', upload_to=upload_to, blank=True, null=True)

    recovery_email = models.EmailField(_('Recovery Email'), blank=True, null=True)
    about_me_email = models.EmailField(_('About Me Email'), blank=True, null=True)

    def __str__(self):
        assert isinstance(self.username, object)
        return self.username

    def save(self, *args, **kwargs):
        self.slug = slugify(self.username, allow_unicode=True)
        super().save(*args, **kwargs)
        self.create_thumbnail()

    @property
    def get_url_path(self):
        return reverse("profile", kwargs={"slug": self.object.slug})

forms.py

class UpdateNameForm(UpdateFormBase):
    class Meta:
        model = User
        fields = ('first_name', 'last_name')

    def __init__(self, *args, **kwargs):
        super(UpdateNameForm, self).__init__(*args, **kwargs)
        self.helper = helper.FormHelper(self)
        self.helper.form_show_labels = False
        self.helper.form_tag = False
        self.helper.layout = layout.Layout(
            layout.Div(
                layout.Div(
                    layout.Div(
                        layout.HTML(fieldtostring("required", "autofocus", type="text", name="first_name", value="")),
                        layout.HTML(valuetolabel("first_name", "First Name")),
                        css_class="md-form",
                    ),
                ),
                layout.Div(
                    layout.Div(
                        layout.HTML(fieldtostring("required", type="text", name="last_name", value="")),
                        layout.HTML(valuetolabel("last_name", "Last Name")),
                        css_class="md-form",
                    ),
                ),
            )
        )

myaccount/change_name.html

<div class="modal-body" style="padding-top: 0px;">
  <form method="post" action="{% url 'change_name'  %}">
    {% crispy form %}
    <div class="btn-group float-right" role="group" aria-label="Basic example">
      <button type="button" class="btn btn-flat btn-sm float-right btn-custom-0" data-dismiss="modal">
        <span class="text-secondary custom-text-3">Cancel</span>
      </button>
      <button type="submit" class="btn btn-flat btn-sm float-right btn-custom-0"><span class="text-primary custom-text-3">Done</span></button>
    </div>
  </form>
</div>

Since the code is pretty long, please just assume that all the methods (like the layouts, which belongs to django-crispy-form) are imported and declared properly.

Helps appreciated 🙏