Kunming station Redemption (Online purchasing)

I bought ticket from Kunming-Lijiang. My friend visited Kunming and I asked her to help me to purchase one. But when she go to the station, she can't buy because the officer said that they need passport of the passenger. So, my friend's friend help to get one via online booking (using one of the machine).

She sent to me a picture and the details of the success transaction. She said that I need to claim it at the railway.

My question is, where should I go at the railway station to redeem my ticket? How should I know to ensure that my seat has been booked?