Почему не загружаются изиображения в профиль пользователя?

    from django.db import models
    from django.contrib.auth.models import User
    from django.db.models.signals import post_save
    from django.dispatch import receiver
 
 
    class Profile(models.Model):
        user = models.OneToOneField(User, on_delete=models.CASCADE, 
        related_name='profile')
        avatar = models.ImageField(User, upload_to='media/', default='no_image.jpg', 
        null=True, blank=True)
 
    @receiver(post_save, sender=User)
    def create_user_profile(sender, instance, created, **kwargs):
        if created:
             Profile.objects.create(user=instance)

    class ProfileForm(forms.ModelForm):
      class Meta:
           model = Profile
           fields = ('user', 'avatar')

    def avatar_img(request):
         profile = request.user
         form = ProfileForm(instance=request.user)
         if request.method == 'POST':
              form = ProfileForm(request.POST, request.FILES, instance=profile)
             if form.is_valid():
             form.save()
        context = {'form': form}
        return render(request, 'user.html', context)

     <img src="{{ request.user.profile.url }}" class="avatar">
 
     <form method="POST" action="{% url 'user_profile:avatar' %}" 
     enctype="multipart/form-data">
       {% csrf_token %}
      {{form.as_p}}
     <input class="btn btn-primary" type="submit">
     </form>