docuseal/app/views/submissions/new.html.erb

<%= render 'shared/turbo_modal' do %>
  <%= form_for '', url: template_submissions_path(@template), data: { turbo_frame: :_top } do |f| %>
    <div>
      <%= f.label :emails %>
      <%= f.text_area :emails, required: true %>
    </div>
    <div>
      <%= f.check_box :send_email, { onchange: "message_field.classList.toggle('hidden', !event.currentTarget.checked)" } %>
      <%= f.label :send_email %>
    </div>
    <div id="message_field" class="hidden">
      Hi There,
      <%= f.text_area :message, value: SubmissionMailer::DEFAULT_MESSAGE, required: true %>
      Thanks,
      <%= current_account.name %>
    </div>
    <%= f.button button_title %>
  <% end %>
<% end %>