int LED = 13;
int Button = 12;

void setup() {
  pinMode(LED , OUTPUT);
  pinMode(Button, INPUT_PULLUP); // Enables internal pull-up resistor
}

void loop() {
  int Click = digitalRead(Button);
  
  if (Click == LOW) { // Button is pressed (active LOW)
    digitalWrite(LED, HIGH);
  } else {
    digitalWrite(LED, LOW);
  }
}