notification_banner.html.erb

<%= tag.div(class: classes.append(success_class).compact, **html_attributes, role: "region", aria: { labelledby: title_id }, data: data_params) do %>
  <div class="govuk-notification-banner__header">
    <%= content_tag(title_tag, class: "govuk-notification-banner__title", id: title_id) do %>
      <%= title %>
    <% end %>
  </div>
  <div class="govuk-notification-banner__content">
    <% headings.each do |heading| %>
      <p class="govuk-notification-banner__heading">
        <% if heading.text.present? %>
          <%= heading.text %>
          <% if heading.link_target && heading.link_text %>
            <%= link_to(heading.link_text, heading.link_target, class: "govuk-notification-banner__link") %>.
          <% end %>
        <% else %>
          <%= heading.content %>
        <% end %>
      </p>
    <% end %>

    <%= content %>
  </div>
<% end %>