How to change Flask WTForm field value in HTML using javascript?

Solution

class ExampleForm(FlaskForm):
    response = HiddenField()
    submit = SubmitField()

@app.route('/', methods=['GET', 'POST'])
def index():
    form = ExampleForm(request.form)
    if form.validate_on_submit():
        print(form.response.data)
    return render_template('index.html', **locals())


  {{ form.csrf_token }}
  {{ form.response }}
  {{ form.submit }}