Unity Relay
Important: The Relay package is deprecated in Unity 6 and will not receive further updates. The Relay SDK is now part of the unified Multiplayer Services package (com.unity.services.multiplayer). Migrate to that package to access ongoing support and improvements.
Please consult the documentation here: https://docs.unity.com/relay/
You can also go to the Relay Dashboard to learn more, find documentation, and get support.