Travel from Chongqing to Chengdu by railway

Hello,

I will be arriving at Chongqing airport and I would like to book a ticket by railway from Chongqing to Chengdu for that same day. I would like to book the ticket in advance because they could be sold out. But for booking tickets, the only options given for delivery are a hotel, or a private address. Since I will not be staying in a hotel in Chongqing, where can my tickets are delivered?
Thank you for your answer!