django upload files using class based view

Question

I am facing this problem when I try to upload files it doesn't work from the html page but from the admin panel it works.

my model is:

class contrat(models.Model):
        contrtID     = models.CharField(max_length=25,unique=True)
        SHRPath      = models.FileField(upload_to='contrats/')
        post_date    = models.DateTimeField(default=timezone.now)
        author       = models.ForeignKey(User,on_delete=models.CASCADE)
        def __str__(self):
            return self.contrtID
        def delete(self, *args, **kwargs):
            self.SHRPath.delete()
            super().delete(*args, **kwargs)
        def get_absolute_url(self):
            return reverse('Scheduling')
        class Meta:
            ordering = ('-post_date',)

The form is:

class contrat_F(forms.ModelForm):
    contrtID     = forms.CharField(label='Code',max_length=25)
    class Meta:
        model= contrat
        fields=('contrtID','SHRPath')

The Views.py is:

class Contratadd(LoginRequiredMixin, CreateView):
    model = contrat
    template_name = 'Home/Scheduling/Add_contract.html'
    form_class=  contrat_F
    def form_valid(self, form):
        form =contrat_F(request.POST, request.FILES)
        form.instance.author = self.request.user
        return super().form_valid(form)

the urls.py is:

path('Add_Contrat/', views.Contratadd.as_view(), name='Add_Contrat'),

the page html code is:

<form action="" method="post" enctype="multipart/form-data">
    {% csrf_token %}
    <div class="border p-2 mb-3 mt-3 border-secondary">
        <div class="form-row">
            <div class="form-group col-md-12 mb-0">
                {{ form.contrtID|as_crispy_field }}
            </div>
        <div class="form-row">
            <div class="form-group col-md-12 mb-0">
                {{form.SHRPath}}
            </div>
        </div>
    </div>
    <input class="btn btn-success mb-4" type="submit" value="ADD Contrat">
</form>

THIS IS IN THE PAGE

BUT IT DOESN'T UPLOAD THE FILE! where is my mistake please? the error is:

name 'request' is not defined