answer text_fields are not showing up

classes.rb

class Questionnaire < ApplicationRecord
  has_many :questions
  has_many :member_questionnaires
  has_many :users, through: :member_questionnaires
  accepts_nested_attributes_for :questions
end

class Question < ApplicationRecord
  belongs_to :questionnaire
  has_one :answer
  accepts_nested_attributes_for :answer
end


class Answer < ApplicationRecord
  belongs_to :question
end

https://www.youtube.com/watch?v=WxqmaKk79Hw

edit.haml

%h1
  questionnaires#edit

= form_for @questionnaire do |f|
  - @questionnaire.questions.each do |q|
    %h1
      = q.description
    - f.fields_for :question, q do |question_fields|
      %h1
        not showing up
      - question_fields.fields_for :answer, q.build_answer do |answer_fields|
        %h1
          not showing up 2
        = answer_fields.text_field :description

  = f.submit