We will do a better job explaining this soon and also provide binaries. For now there are a few possibilities:

1. Grayjay can cast to an FCast receiver

2. There are some terminal clients and a nautilus plugin, but we don't provide binaries (yet). These can be used to cast local media and remote media https://gitlab.com/futo-org/fcast/-/tree/master/client

3. Someone made a yt-dlp client that can cast to FCast: https://git.sr.ht/~shironeko/fcast/tree/yt-dlp/item/clients/...

4. Cloudfstream supports it: https://github.com/recloudstream/cloudstream/blob/master/app...