Answer 1

In order to use an audio file on sololearn you must have it hosted somewhere. Dropbox is one of the more common places to store it. You could also host the files in a website hosting platform (I would suggest 000webhost if you don’t want to spend anything). After your file is hosted, you need to get its location. Paste the location in the audio tag:

<audio src=“location”></audio>

Answer 2

You can use any audio file that is already online, by passing it's link as location. In the example, I use a video tag instead of audio, but they are not so different.

<video src="http://62.138.24.196/tb/9/2f/john_blaq_nekwataako_official_audio_h264_53009.mp4?play" controls></video>