There are 2 repositories under godot-multiplayer topic.
Client/Server Authoritative Multiplayer Addon for the Godot Engine
Unofficial Epic Online Services wrapper for Godot Engine 4.2 (EOSG) (includes demo project)
Godot 4 Multiplayer (Authoritative Server) Demo + Single Player 3D Character Controller
Top Down Survival multiplayer game.
Godot 2D Multiplayer template (3.5)
Online game with dedicated server at Godot.
A Very Simple C# TCP Networking library for making networking code less painful