The SwagLyrics extension extends Spotify Web Player support to the SwSpotify (https://swaglyrics.dev/SwSpotify) python library. This allows developers to make cross-platform applications that interact with Spotify without worrying about each OS themselves. The extension is open source at https://github.com/SwagLyrics/SwagLyrics-Chrome-Extension. If you're an end user redirected to the extension by a dev, then all you need to do is to install this extension to enable support for the Spotify Web Player!