The Jellyfin Cast Web Receiver is the frontend used when casting to a Google Cast capable device. It is used by default when casting from the Jellyfin Android app or Jellyfin web client.
A `stable` and `unstable` version of this app are already included in the Jellyfin server. There is no need to separately install this project. To host your own version (for developing) see `CONTRIBUTING.md`.
Anything related to your non-cast device (e.g. your phone, browser, other device) or anything about the inclusion of casting for a specific client (e.g. casting from the iOS app).
Any issues/features related to that: check the respective repository.
Jellyfin allows switching between a `stable` and `unstable` version of the client. Go the client of your choice and: `user` -> `settings` -> `playback` -> `Google Cast version`.