radio buttons with simple input

dear stackoverflow!

Professionals, please help.

i need to implement a form like this in Django:

If a user enters something in the “another amount” field, the radio buttons become disabled.

I really have no idea.

my html:

                        <div class="payment__amount">
                            <div class="payment__amount__1">
                                <div class="form-check payment__amount__check">
                                    {{ form.amount_select.0 }}
                                </div>
                                <div class="form-check payment__amount__check">
                                    {{ form.amount_select.1 }}
                                </div>
                            </div>
                            <div class="payment__amount__2">
                                <div class="form-check payment__amount__check">
                                    {{ form.amount_select.2 }}
                                </div>
                                <div class="form-check payment__amount__check">
                                    {{ form.amount_select.3 }}
                                </div>
                            </div>
                        </div>
                        {{ form.amount_input }}

my forms.py

CHOISES = [
    ('50', '50'),
    ('100', '100'),
    ('200', '200'),
    ('500', '500')
]


class CheckoutForm(forms.Form):
    amount_select = forms.IntegerField(widget=forms.RadioSelect(choices=CHOISES))
    amount_input = forms.IntegerField(widget=forms.TextInput(attrs={'placeholder': "another amount"}))

Thank you very much!