Here's a simple example of a sketch that uses BlynkSimpleEsp8266 to control an LED connected to an ESP8266 board:

void setup() { Serial.begin(115200); Blynk.begin(auth, ssid, password); pinMode(LED_PIN, OUTPUT); }

You can download the BlynkSimpleEsp8266 library ZIP file from the official Blynk website or from the Arduino Library Manager. Once you've downloaded the ZIP file, you can install it in the Arduino IDE using the " Sketch > Include Library > Add .ZIP Library..." menu option.

#include <BlynkSimpleEsp8266.h>

void loop() { Blynk.run(); }