_locale_selector.html.erb

<% available_locales = current_store.available_locales %>
<% if available_locales.many? %>
  <li id="locale_selector" data-hook>
    <%= form_tag spree.select_locale_path, class: 'navbar-form' do %>
      <div class="form-group">
        <label for="switch_to_locale" class="sr-only">
          <%= Spree.t(:'i18n.language') %>
        </label>
        <%=
          select_tag(
            :switch_to_locale,
            options_for_select(
              available_locales.map do |locale|
                [I18n.t('spree.i18n.this_file_language', locale: locale, default: locale.to_s, fallback: false), locale]
              end.sort,
              selected: I18n.locale
            ),
            class: 'form-control'
          )
        %>
        <noscript><%= submit_tag t("spree.select") %></noscript>
      </div>
    <% end %>
  </li>
<% end %>