Sim City

For SC 2013, purchased from Origin, it is stored in the Game Library in the Origin Client software. It connects your player account to your game. 

@5L9R-8RVQ-KDXL-U 

You received your answer. 

@5L9R-8RVQ-KDXL-U

The thing you put as a username, but didn't put completely. That's your product code. Your name or nickname should go in there, and that code should, in turn, go to Origin so you can register your game. 😉