This should be a special page where you specify the parameter for the audio (see T402522: Make a request to download an article). Article can use a field with type "title" if HTMLForm is used.

If the selected article already is available for download you should get a link to it. Possibly multiple versions if there are, either because of different parameters or if there's been changes to the article. You should be able to tell if any of these downloads match what you want.

If there's no version available, or you want to make a different one, there's a button to request download.