How to define the Session Schema when using EOSG?

When using EOSG to create a Session one of the parameters is Schema Name.

OnlineServices = UE::Online::GetServices();
SessionsInterface = OnlineServices->GetSessionsInterface();
UE::Online::FCreateSession::Params Params;
Params.bAntiCheatProtected = false;
Params.SessionName = TEXT(“DEV Test Session”);
Params.LocalAccountId = AccountInfo.AccountId;
Params.bIsLANSession = false;
Params.bPresenceEnabled = true;
Params.SessionSettings.JoinPolicy = UE::Online::ESessionJoinPolicy::Public;
Params.SessionSettings.NumMaxConnections = 16;
Params.SessionSettings.SchemaName = FName(“GameSession”);

For Lobbies in EOSG the schema value points to settings that must be configured in the DefaultEngine.ini.

Example:

[OnlineServices.Lobbies]
+SchemaDescriptors=(Id=“GameLobby”, ParentId=“LobbyBase”)

!SchemaCategoryAttributeDescriptors=ClearArray
+SchemaCategoryAttributeDescriptors=(SchemaId=“LobbyBase”, CategoryId=“Lobby”, AttributeIds=(“SchemaCompatibilityId”, “ExampleSearchableLobbyAttribute”))
+SchemaCategoryAttributeDescriptors=(SchemaId=“LobbyBase”, CategoryId=“LobbyMember”)

So, I assume a similar structure is needed to define the custom attributes needed to make a Session.
However unlike Lobbies I have not been able to find any documentation outlining examples or anything else to guide a developer on how to define a Session schema.

Can anyone point me to an example or other documentation?

Thanks
J.