String inputCommand;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(2, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available()){
    inputCommand = Serial.readString();
    inputCommand.trim();
    inputCommand.toLowerCase();
    if(inputCommand == "on") {
      digitalWrite(2,HIGH);
    }
    else if(inputCommand == "off") {
      digitalWrite(2, LOW);
    }
    else {
      Serial.println("Invalid Command");
    }
  }
}