Where to store player elo when implementing skill based matchmaking!

Hello everyone!

I'm trying to implement skilled based matchmaking using LobbyType.SqlLobby.

I'm following the code examples from this video

My question is, where should I store elo (skill rating) of every player? My game is integrated with PlayFab and one option could be to store it there, but I'm not sure if this is a correct approach.

PS.

I'm completely new to this, could you please suggest some good examples with code on how to correctly implement skill based matchmaking.

Thanks!