{% load export_url from django_tables2 %}

<div class="dropdown">
  <button class="btn btn-sm btn-secondary dropdown-toggle"
          type="button"
          data-bs-toggle="dropdown"
          aria-expanded="false">
    <i class="bi bi-download"></i> Download
  </button>
  <ul class="dropdown-menu">
    {% for format in view.export_formats %}
      <li>
        <a class="dropdown-item" href="{% export_url format %}">{{ format }}</a>
      </li>
    {% endfor %}
  </ul>
</div>