How do I fill out a profile/update a profile when available?

Question

Django

Hello.
The situation is this:
There is a user profile, where there is additional information (Avatar, about myself, what I offer).
Task: to make a profile filling form that would accept fields (not necessarily all), and update them (not necessarily all).

class Profile_Form(forms.Form):
    avatar = forms.ImageField(label='Загрузить Аватар', required=False)
    myself = forms.CharField(widget=forms.Textarea(attrs={'class': 'course_review_form_width'}), label='О себе', required=False)
    myoffer = forms.CharField(widget=forms.Textarea(attrs={'class': 'course_review_form_width'}), label='Что предлагаю', required=False)

def update_profile(request, add_id):
    token = {}
    token.update(csrf(request))
    if request.user.is_authenticated():
        current_user = request.user
        if request.POST:
            # profilepage = Profile.objects.get(id = add_id)
            form = Profile_Form(request.POST or None, request.FILES or None)
            if form.is_valid():
                avatar = form.cleaned_data['avatar']
                myself = form.cleaned_data['myself']
                myoffer = form.cleaned_data['myoffer']
                profile_obj = Profile(user=current_user, avatar=avatar, myself=myself, myoffer = myoffer)
                profile_obj.save()
                return redirect('/profile'+ add_id, token)
            else:
                return redirect('/profile'+ add_id, token)
        else:
            return redirect('/profile'+ add_id, token)
    else:
        return redirect('/profile'+ add_id, token)

Now the form is filling out well. But:
- if there is no image, it gives an error that the file will not be found. Although I would like to indicate that the field is optional.
- Unable to update the field. Although the documentation says that the save() method is automatically determined to save or update.