Is it possible to put a form in a thickbox?

I am trying to popup a flashcard form in the shadow box. I got the format of this implementation from the thickbox codex.

<div id="pinyin-english-cards" style="display:none;">
<p>
          <iframe style="border: 0;" src="https://quizlet.com/8885855/flashcards/embedv2" width="100%" height="410"></iframe>
</p>
</div>

<a href="#TB_inline?inlineId=pinyin-english-cards" class="thickbox">Pinyin to English Flashcards</a>

Thanks!

https://www.ads-software.com/plugins/auto-thickbox/