This project demonstrates how to use the Jam Launch addon to make a multiplayer game in Godot 4. The Jam Launch addon simplifies deployment and hosting of multiplayer games.
Developer features require a Jam Launch account with a positive credit balance. You can sign up for an account here.
You can play a deployed version of the example project here.
Jam Launch credits can be purchased and used to host your project on Jam Launch infrastructure. You only pay for the resources you use, and deployments can be done in one click from the addon's editor plugin:
If you don't want to buy credits, you can still run games in local hosting mode with the addon. This allows you to verify game functionality and compatibility with Jam Launch.