PlatformIO project for Arduino Uno R3 (ATmega328P mikrocontroller)
For pinout of your Ardiuno board see https://github.com/Bouni/Arduino-Pinout
The four anode connections of the four LEDs, which are directly connected to the Arduino board, are located at PWM pins 5 (PC6), 6 (PD7), 9 (PB5), and 10 (PB6). The ground connections of the LEDs must be connected to the ground of the Arduino board.
The (3-pin) potentiometer must be connected to 5V, ground, and analog input A1 (pin 19).