Multiple local players joining online game

I cannot figure out how to do this. Currently what I am wanting to do is as follows: I have a screen where player 1 can pick a character and customize it, and three others can press A to join and customize their own characters. When they are all ready, these four character customizations host or join a server, where playerobjects are spawned for them and their customization options are applied to their playerobjects.

That is, the players all join, and then they are added to the server. When I try to use ClientScene.addplayer, though, it says I need a connection. Do I need to already be hosting or joining a server to add multiple local players?

Thanks

 

I understand the concept of transferring data between scenes - it's the multiple local players going online that has me confused. If the sample project has that feature, I cannot find it.

 

I really cannot see how the hook has anything to do with multiple local players joining an online match. It looks like it is only for transferring traits from a lobby prefab to an in game prefab?

 

Ah, okay. I did notice that AddPlayer() requires an established connection, which is why you starthost first. But what if I want to have a party of local players join as a client? Can I have everybody locally join, and then have that party join a game hosted elsewhere?

[EDIT]

I am using a standard NetworkManager, too, implementing a custom lobby system instead

 

Thanks. Okay, I have the server creating the correct number of players. But how do I transfer the data from the client scene to the server scene? I have the client call AddPlayer() for each local player, but the server at that point doesn't know what options the client had select when it's creating its player with AddPlayerForConnection().

[edit]
I guess I should just change my code so that the items the players select are stored by string and then can be synced to the server, rather than stored by reference