How to add disabled attribute to input elements generated by MultipleChoiceField?

Question

Django

Hello!
I have a form with a MultipleChoiceField field. The form outputs data from the CHOICES tuple.
models.py:

class Requirement(models.Model):
    code = models.UUIDField(_('Code'), primary_key=True, default=uuid.uuid4, editable=False)
    symbol = models.CharField(_('Symbol'), max_length=250)
    name = models.CharField(_('Name'), max_length=250)

forms.py:

CHOICES = (
        ('A', 'Name A'),
        ('B', 'Name B'),
        ('C', 'Name C'),
)

class RequirementAddForm(forms.ModelForm):
    symbol = forms.MultipleChoiceField(required=False, widget=forms.CheckboxSelectMultiple, choices=CHOICES,)

    class Meta:
        model = Requirement
        fields = ('symbol',)

view.py:

if form.is_valid():
            list = dict(REQUIREMENTS_CHOICES) # {'C': 'Name C', 'A': 'Name A', 'B': 'Name B'}
            symbols = form.cleaned_data.get('symbol') # ['A', 'B', 'C']
            requirement = form.save(commit=False)
            for symbol in symbols:
                requirement.symbol = symbol
                requirement.name = list[symbol]
                requirement.save()

MultipleChoiceField in template generates a list like this:

<ul id="id_symbol">
   <li>
      <label for="id_symbol_0" disabled="">
          <input id="id_symbol_0" name="symbol" value="A" type="checkbox">Name A
      </label>
   </li>
   <li>
      <label for="id_symbol_1" disabled="">
          <input id="id_symbol_1" name="symbol" value="B" type="checkbox">Name B
      </label>
   </li>
   <li>
      <label for="id_symbol_2" disabled="">
          <input id="id_symbol_2" name="symbol" value="C" type="checkbox">Name C
      </label>
   </li>
</ul>

Question : How can I add the disabled attribute to some input elements? Is it possible? For example, add the disabled attribute to the third input?