class TypeBackup(models.Model):
    id = models.IntegerField(primary_key=True, verbose_name="ID")
    type = models.CharField(max_length=30, blank=False, null=False, verbose_name="Тип резервного копирования")
class Jobs(models.Model):
    ...
    type_backup = models.ForeignKey(TypeBackup, null=False, blank=False)
class AddJobForm(ModelForm):
    class Meta:
        model = Jobs
        fields = [..., 'type_backup']
        widgets = {...
                   "type_backup":forms.Select(attrs={"size": 1})}