- Download and install Stream What You Hear (https://www.streamwhatyouhear.com/download/).
- Launch the app using the Start menu shortcut.
- Right-click on the app’s icon in the system tray.
- Go to Tools > HTTP Live Streaming.
- Copy the on-screen URL.
- Open the Sonos app.
- Go to Manage > Add Radio Station.
- Paste in the URL and give the link a name.
- Click OK.
(Full details from a site I found on Google;
https://www.makeuseof.com/tag/stream-computer-audio-output-sonos/).