const byte buttonGpio = 4;
const byte ledGpio = 6;

int buttonState = 0;

void setup()
{
  pinMode(buttonGpio, INPUT);
  pinMode(ledGpio, OUTPUT);
}

void loop()
{
  buttonState = digitalRead(buttonGpio);

  if (buttonState == HIGH)
  {
    digitalWrite(ledGpio, HIGH);
  }
  else
  {
    digitalWrite(ledGpio, LOW);
  }
}