LED not glowing - arduino

Question

I a beginner to IoT. I want to glow LED connected to arduino for this I have made connections as described below, also see the image of breadboard attached here.
LED Connections
Connected
Arduino GND to one leg of LED and 3.3V to another leg of LED.
My Arduino program is-
void setup() {
Serial.begin(9600);
// connect to wifi.
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Serial.print("connecting");
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(500);
}
Serial.println();
Serial.print("connected: ");
Serial.println(WiFi.localIP());
Firebase.begin(FIREBASE_HOST, FIREBASE_AUTH);
Firebase.set("LED_STATUS",0);
}
int n = 0;
void loop() {
// get value
n = Firebase.getInt("LED_STATIS");
if (n == 1) {
Serial.print("LED IS ON");
digitalWrite(D1,HIGH);
return;
}else{
Serial.print("LED IS OFF");
digitalWrite(D1,LOW);
return;
}
delay(1000);
}
Serial monitor shows LED is ON as shown in screenshot.
Serial Monitor

Answer 1

i think you should declare pinMode in setup, and you put LED in D0
#define LED D0 // Led in NodeMCU at pin GPIO16 (D0).
void setup() {
pinMode(LED, OUTPUT); // LED pin as output.
}
void loop() {
if (n == 1) {
Serial.print("LED IS ON");
digitalWrite(LED ,HIGH);
return;
}else{
Serial.print("LED IS OFF");
digitalWrite(LED ,LOW);
return;
}
}
note that it has built-in LED, but its active low, it should glow when logic is 0
and you should using pull-up resistor, because you can't depend current supply from GPIO pin since its only provide 12mA