You can follow the instructions in the official video, starting from 17:48: https://youtu.be/-bi1iFsd1q4 (opens in a new tab)

Download this code and open it in your Arduino IDE, connect it to your Arduino and upload it https://gist.github.com/minhviet0308/b4aacec438c96ed28a8d8eedc74db842 (opens in a new tab)

When you run this test, the car will face to the front at 90, turn left, and turn right, then faces front again.

Note:

• Make sure that the orange motor is connected to PIN 9, the blue motor is connected to PIN 10
• The motor can turn anywhere from 0 to 180 degrees
• Line 6 in the code is the most important line, it dictates the angle which the motor sees as the 'front' of the car
• Make sure the car's front orientates with the board. If it doesn't, slightly change 90 up or down until it faces the right direction.
• Line 8 and 9 in the code are the turning angles for left and right, change this however you like with respect to your front angle (ex: if you front is 90, then your turning angles are 40 and 140)
• Don't screw the front wheels too tightly, as it hinders the steering of the car

For fun:

• In the void setup() function, you will see some commented lines with 'cat' in them (14, 15, 19, 22). These lines will run the ultrasound sensor in the front of the car (the cat face), making it turn left, right, then front, just like the motor for the wheel. Try uncommenting them and upload the code.
• Copy and put the code in the setup() function in the void loop() function, and watch the car rotates repeatedly.