This is useful for language lessons or if you simply want to add multiple languages to give viewers the option to watch in a different language or their native language.
You can provide HLS videos with multiple audio tracks by adding the link to Spotlightr. Spotlightr will recognize the additional audio tracks and enable their selection.
You can also simply add additional audio track to any uploaded video file. Navigate to the Player tab >> Captions & Transcripts >> Additional Audio Tracks:
Once added, viewers will have a new icon in their player controls like this: