Relay on off

Code-
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(2, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
digitalWrite(2, HIGH); // turn the LED on (HIGH is the voltage level)
delay(500); // wait for a second
digitalWrite(2, LOW); // turn the LED off by making the voltage LOW
delay(500); // wait for a second
digitalWrite(2, LOW); // turn the LED off by making the voltage LOW
delay(500); // wait for a second
digitalWrite(2, HIGH); // turn the LED on (HIGH is the voltage level)
delay(500); // wait for a second
}