It's to the right of the door exiting the south concourse ticket office. As I said, when I saw all the English on the screen, I thought it might accept passports -- no sense for English if it's Chinese ID-only -- but I couldn't bring any instructions up, and didn't see any slot for a passport.

As usual in Chinese ticket offices, there's no information desk where you can make inquiries about something like this, though if you've got time I suppose you can ask at the office of the 站长 inside.