Show node links in modal buttonpane
Ah, I just figured out from core/misc/dialog/dialog.ajax.js that I need wrapper with class form-actions.
&lt;div class=&quot;form-actions&quot;&gt;
  &lt;a href=&quot;mailto:test@example.com&quot; class=&quot;button&quot;&gt;Send email&lt;/a&gt;
&lt;/div&gt;