GameSparks Realtime is intended for session-based gameplay, rather than persistent, hosted game multiplayer games.

Rather than hosts, GameSparks has peer-to-peer multiplayer with the RT host acting as an intermediary server for intercepting packets.

When a match is successful, you could choose a "game leader". Most likely this would be the player assigned a peerId of 1. You could then have a listener in your RT Script which handles a config event sent up from that peerId. You can read more on building RT Scripts here.

For dedicated hosts, you would need to use a separate hosting solution, such as AWS EC2 for instance. Usually this also requires a back end - in this case, you could use GameSparks along with a hosting provider.