netbox/netbox/templates/inc/sync_warning.html

{% load buttons %}
{% load perms %}

{% if object.data_file and object.data_file.last_updated > object.data_synced %}
  <div class="alert alert-warning" role="alert">
    <i class="mdi mdi-alert"></i> Data is out of sync with upstream file (<a href="{{ object.data_file.get_absolute_url }}">{{ object.data_file }}</a>).
    {% if request.user|can_sync:object %}
      <div class="float-end">
        {% sync_button object %}
      </div>
    {% endif %}
  </div>
{% endif %}