to include a audiofile, say for example bensound-acousticbreeze.mp3, in a fact with audiocontrols for direct playback. you need the download-link of said download-fact.
then, edit the fact you want to include the audiofile with controls in, and in HTML-Mode add:
<audio src="http://doku.factlink.net/fsDownload/bensound-acousticbreeze.mp3?v=1&forumid=101&id=5938932&directdownload=1" controls preload></audio>
where in src=" " you paste the download-link and add "&directdownload=1" like in the example above
the endresult should look like this: