How to eat in the canteen of Sun Yat-sen University North Campus?

Outsiders eat in the dining hall of the North Campus of Sun Yat-sen University, because it is open to the public. According to official website of Sun Yat-sen University, all the canteens of Sun Yat-sen University are open to the public. Foreigners can buy meal tickets in cash, and the price is 25% higher than the student price.