Collecting data for 'hstore' field

_form.html.erb

<%=form_with(model: user, local: true, :html=> {class: 'ui form'}) do |form| %>
  <% if user.errors.any? %>
   <div id="error_explanation">
    <h2><%= pluralize(users.errors.count, "error") %> prohibited this user from being saved:</h2>
      <ul>
      <% user.errors.full_messages.each do |message| %>
      <li>
        <%=message %>
      </li>
      <% end %>
      </ul>
    </div>
  <% end %>
 <div class="fields">
      <div class="six wide field">
          <%=form.label :first_name %>
          <%=form.text_field :first_name, id: :user_first_name %>
      </div>

      <div class="six wide required field">
          <%=form.label :last_name %>
          <%=form.text_field :last_name, id: :user_last_name %>
      </div>
  </div>
  <div class="four wide field">
      <%=form.label :email %>
      <%=form.email_field :email, id: :user_email %>
  </div>

  <div class="four wide field">
      <%=form.label :phone %>
      <%=form.telephone_field :phone, id: :user_phone %>
  </div>
<!-- #### ADDRESS FIELD STARTS HERE #### -->
<div class="fields">
    <%=form.fields_for :address do |a| %>
        <div class="field">
            <label>Street address </label>
            <%= a.text_field :street_address, id: :street_address %>
        </div>
        <div class="field">
            <label>City </label>
            <%= a.text_field :city, id: :city %>
        </div>
        <div class="two wide field">
            <label>State </label>
            <%=a .text_field :state, id: :state %>
        </div>

        <div class="field">
            <label>Zip </label>
            <%= a.number_field :zip_code, id: :zip_code %>
        </div>
</div>
<%end%><!-- #### ADDRESS FIELD ENDS HERE #### -->

  <div class="two wide field">
      <%=form.label :eye_color %>
      <%=form.text_field :eye_color, id: :user_eye_color %>
  </div>

  <div class="six wide field">
      <label>Date of birth</label>
      <%=form.date_field :dob, id: :user_dob %>
  </div>


<br>
<div class="actions">
    <%=form.submit 'Submit', class: 'ui primary button' %>
</div>
<% end %>