OnlineSubsystem

DEFAULTENGINE.INI

Edit your DefaultEngine.ini file located in Project\Config\DefaultEngine.ini and add the following configuration, remember to change out the DefaultPlatformService to EOS (if previously using Steam or any other Service)

[OnlineSubsystem]
DefaultPlatformService=EOSCore

[/Script/OnlineSubsystemEOSCore.NetDriverEOSCore]
NetConnectionClassName="OnlineSubsystemEOSCore.NetConnectionEOSCore"
bIsUsingP2PSockets=true

[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="OnlineSubsystemEOSCore.NetDriverEOSCore",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")