We went to Xinjiang, and now we bought a sleeping berth in Guangyuan, can we pay for the sleeping berth after getting on the train?

If there are spare beds on the train, it can be filled, if there are no empty beds, it cannot be filled. In addition, in this special period, it is required to strictly control the passenger load factor. If you are refused to make up the ticket, you must get off at Guangyuan. (For reference, please refer to the actual situation of the railway.)