Local Network OTA ESP8266

NetworkConfig.ino

#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>
#include <ESP8266WebServer.h>

#ifndef STASSID
#define STASSID "Jalukan"
#define STAPSK  "12345678"
#endif

const char* ssid = STASSID;
const char* password = STAPSK;
ESP8266WebServer server; 
 
bool ota_flag = true;
uint16_t time_elapsed = 0;

// setup()
void setupOTA() {
  Serial.println("Booting");
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    Serial.println("Connection Failed! Rebooting...");
    delay(5000);
    ESP.restart();
  }

   ArduinoOTA.setPasswordHash("21232f297a57a5a743894a0e4a801fc3");

  ArduinoOTA.onStart([]() {
    String type;
    if (ArduinoOTA.getCommand() == U_FLASH) {
      type = "sketch";
    } else { // U_FS
      type = "filesystem";
    }

    // NOTE: if updating FS this would be the place to unmount FS using FS.end()
    Serial.println("Start updating " + type);
  });
  ArduinoOTA.onEnd([]() {
    Serial.println("\nEnd");
  });
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
  });
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    if (error == OTA_AUTH_ERROR) {
      Serial.println("Auth Failed");
    } else if (error == OTA_BEGIN_ERROR) {
      Serial.println("Begin Failed");
    } else if (error == OTA_CONNECT_ERROR) {
      Serial.println("Connect Failed");
    } else if (error == OTA_RECEIVE_ERROR) {
      Serial.println("Receive Failed");
    } else if (error == OTA_END_ERROR) {
      Serial.println("End Failed");
    }
  });
  ArduinoOTA.begin();
  Serial.println("Ready");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  server.on("/restart",[]() {
    server.send(200, "text/plain", "Restarting...");
    delay(1000);
    ESP.restart();
  });

  server.on("/setflag",[]() {
    server.send(200, "text/plain", "Setting Flag...");
    ota_flag = true;
    time_elapsed = 0;
  });
  
  server.begin(); 
}

// placed inside loop() before your program
void handleOTAIfAny() {
  if(ota_flag) {
    uint16_t time_start = millis();
    while(time_elapsed < 15000) {
      ArduinoOTA.handle(); 
      time_elapsed = millis()-time_start;
      delay(10);
    }
   ota_flag = false;
  }
  server.handleClient();
}