Enter the trade city from any entrance on the first floor and find the elevator or stairs leading to the third floor. Usually, there will be a sign next to the elevator to indicate the floor you want to go to.
Take the elevator or take the stairs to the third floor. In the elevator, you can press the "3" key or directly tell the staff to go to the third floor. If you choose to take the stairs, you need to climb on foot. You can consult the staff, or look at the relevant signs of the trade city to get the most accurate information.