NyxDeveloper

def save(self, *args, **kwargs):
        if not self.id:
            super(Model2, self).save(*args, **kwargs)
            self.model1_set.add(*self.task_set.model.objects.values_list("id", flat=True))

sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.8 1

form.base_fields['field_name'].initial = [
    i for i in form.base_fields['field_name'].choices.queryset.filter(id__in=[1, 2, 3, 4])
]