Direct assignment to the forward side of a many-to-many set is prohibited

class ProfileAboutViewTestCase(TestCase):
    fixtures = [
        'myprofile-fixtures.json'
    ]
 
    @classmethod
    def setUpClass(cls):
        cls.user = User.objects.create(username="User_test", password="qwerty")
 
    @classmethod
    def tearDownClass(cls):
        cls.user.delete()
 
    def setUp(self) -> None:
        self.client.force_login(self.user)
        prod = Product.objects.all()
        self.profile = Profile.objects.create(
            user=self.user,
            balance=5555,
            products=prod.values_list("name", flat=True)
        )
 
        self.profile.save()
 
    def tearDown(self) -> None:
        self.profile.delete()
 
    def test_profile_details(self):
        response = self.client.get(reverse("myprofile_app:profile_details"))
        self.assertContains(response, "User_test")
        self.assertContains(response, "5555")
        self.assertContains(response, self.profile.products)

class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, default=None)
    balance = models.DecimalField(default=0, max_digits=8, decimal_places=2)
    products = models.ManyToManyField('Product', related_name='products')
    proposition = models.ForeignKey('Proposition', on_delete=models.CASCADE, default=None, blank=True, null=True)
 
    def __str__(self):
        return self.user.username
 
    def get_proposition(self):
        return self.proposition.name
 
 
class Product(models.Model):
    name = models.CharField(max_length=100)
    price = models.DecimalField(default=0, max_digits=8, decimal_places=2)
    created_at = models.DateTimeField(auto_now_add=True)
    promotion = models.ForeignKey('Promotion', on_delete=models.CASCADE, default=None, blank=True, null=True)
 
    def __str__(self):
        return self.name
 
    def get_promotion(self):
        return self.promotion.name

class ProfileCreateView(CreateView):
    model = Profile
    fields = "balance", "products"
    success_url = reverse_lazy("myprofile_app:profile_details")
 
    def get(self, request, *args, **kwargs):
        if self.request.user.is_authenticated and self.request.user.id in Profile.objects.values_list('user_id',
                                                                                                      flat=True):
            return redirect(reverse_lazy(
                "myprofile_app:update",
                kwargs={
                    "pk": self.request.user.id
                }, ))
        elif self.request.user.is_authenticated and self.request.user.id not in Profile.objects.values_list('user_id',
                                                                                                            flat=True):
            form = PartialProfileForm(request.POST)
            return render(request, 'myprofile_app/profile_form.html', {'form': form})
        else:
            return redirect(reverse_lazy("myprofile_app:login"))
 
    def form_valid(self, form):
        form.instance.user = self.request.user
        form.save()
        return super().form_valid(form)
 
class ProfileAboutView(LoginRequiredMixin, TemplateView):
    template_name = "myprofile_app/profile_details.html"
    model = Profile
    form_class = ProfileForm
    success_url = reverse_lazy("myprofile_app/profile_details.html")
 
    def get(self, request, *args, **kwargs):
        if self.request.user.is_authenticated and self.request.user.id in Profile.objects.values_list('user_id',
                                                                                                      flat=True):
            promotion_cache_key = f'promotion: {request.user.username}'
            proposition_cache_key = f'proposition: {request.user.username}'
            promotions = Product.get_promotion
            propositions = Profile.get_proposition
            user_cache_data = {
                promotion_cache_key: promotions,
                proposition_cache_key: propositions
            }
            cache.set_many(user_cache_data)
 
            return render(request, 'myprofile_app/profile_details.html', context={
                'promotion': promotions,
                'proposition': propositions
            })
        elif self.request.user.is_authenticated and self.request.user.id not in Profile.objects.values_list('user_id',
                                                                                                            flat=True):
            return HttpResponseRedirect(reverse_lazy("myprofile_app:create"))
        else:
            return render(request, 'myprofile_app/login.html')
 
    def post(self, request, *args, **kwargs):
        form = self.form_class(request.POST, instance=request.user.profile)
        if form.is_valid():
            form.save()
            return HttpResponseRedirect(reverse_lazy("myprofile_app/profile_details.html"))
 
        return render(request, self.template_name, {'form': form})

    def setUp(self) -> None:
        self.client.force_login(self.user)
        prod = Product.objects.all()
        self.profile = Profile.objects.create(
            user=self.user,
            balance=5555,
        )
 
        self.profile.save()
        self.profile.products.add(*prod.values_list("name", flat=True))

self.profile.products.add(prod.values_list("name", flat=True))

    def test_profile_details(self):
        response = self.client.get(reverse("myprofile_app:profile_details"))
        self.assertEquals(response.status_code, 200)
        self.assertContains(response, "User_test")
        self.assertContains(response, "5555")
        for product in self.profile.products.all():
            self.assertContains(response, product.name)

    def setUp(self) -> None:
        self.client.force_login(self.user)
        prod = Product.objects.all()
        self.profile = Profile.objects.create(
            user=self.user,
            balance=5555,
        )
 
        self.profile.save()
        self.profile.products.add(*prod.values_list("name", flat=True))

    def tearDown(self) -> None:
        self.profile.delete()
 
    def test_profile_details(self):
        with translation.override('en'):
            response = self.client.get(reverse("myprofile_app:profile_details"))
        self.assertEquals(response.status_code, 200)
        self.assertContains(response, "User_test")
        self.assertContains(response, "5555")
        for product in self.profile.products.all():
            self.assertContains(response, product.name)

self.profile.products.set(prod.values_list("name", flat=True))