This can be done in an HTML article.
Choose an HTML article from your TinyPortal menu, and add the code below..
Adjust sizes to suit your needs.
<video controls="" style="width: 400px;"><source src="video/your-video.mp4" type="video/mp4" /> Your browser does not support HTML video.</video>
if you wish you can add other text below..
<p>
Video courtesy of
<a href="https://www.link-to-other-page. com/" target="_blank">My video</a>.
</p>
Upload the video to a folder within your forum directory.
Tested with chrome and edge

