• ➯ https://www.hackster.io/vectiva/easy-wireless-communications-with-the-doit-esp-13-shield-09a13a
• ➯ http://blog.ashleytowns.id.au/posts/2018-03-11-duotech-esp13.html
• ➯ https://arduinobasics.blogspot.com/2018/09/esp-13-wifi-shield-web-server.html

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
const char* ssid     = "YOUR_SSID";
const char* password = "YOUR_PASS";
ESP8266WebServer server(80); // HTTP server on port 80
void setup() {
 Serial.begin(115200);    
 WiFi.disconnect(); // Disconnect AP
 WiFi.mode(WIFI_STA);  
 WiFi.begin(ssid, password); // Connect to WIFI network
// Wait for connection
 while (WiFi.status() != WL_CONNECTED) {
  delay(500);
  Serial.println(".");
 }
 Serial.print("Connected to ");
 Serial.println(ssid);
 Serial.print("IP address: ");
 Serial.println(WiFi.localIP());
server.on("/", [](){
  server.send(200, "text/plain", "Hello World");
 });
server.begin(); // Start HTTP server
 Serial.println("HTTP server started.");
}
void loop() {
 server.handleClient();
}