app/views/shared/_announcement.html.erb
<div class="announcement container-fluid <%= Settings.announcement&.html_class || t('blacklight.announcement.html_class') %>">
<div class="row align-items-center">
<div class="col align-content-center">
<p class="text-center mt-2 mb-2 pb-1"><i class="fas <%= Settings.announcement&.icon || t('blacklight.announcement.icon') %>"></i> <%= sanitize Settings.announcement&.message || t('blacklight.announcement.message.html') %></p>
</div>
</div>
</div>