It would look like the "sample" button on Amazon.com. When clicked, the audio starts to play. ( https://amzn.to/3sAGgr6" )
Instead of having to create a new widget for each sample, the URL of the audio can be directly inserted into the code snippet. No image needed, as the widget would be on a catalog page with all other information.
The one Widget could be used for your billing needs, and would apply to ALL samples played, not just one title, as the code is not uinique to one audio file.
The options I would suggest for "universal use" is a variety of "play" buttons, specify width, user-entered text, and background color (or transparent).