i used the arduino uno in wokwi, then i added 1 LED and 1 resistor and changed the resistors property into 220ohms, I then connected the GND in the arduino into the LED, then connected LED into the resistor, lastly I connected the resistor into the 7th digital GPIO pin.
void setup() {
pinMode(7,OUTPUT);
}
void loop() {
digitalWrite(7,HIGH);
delay(400);
digitalWrite(7,LOW);
delay(800);
}
https://wokwi.com/projects/442437205109458945 (know more)