@govbr-ds/core/dist/components/modal/examples/modal-loading.html

Padrão Digital de Governo

<div class="div br-modal xsmall" aria-modal="true" role="dialog" aria-label="Carregando Conteúdo">
  <div class="br-modal-body loading medium">
  </div>
  <div class="br-modal-footer justify-content-around">
    <button class="br-button secondary" type="button">Cancelar
    </button>
  </div>
</div>