#include "EEPROM.h"
#include <WiFi.h>
#include <WiFiClient.h>
#include <WebServer.h>
#include <ESPmDNS.h>
#include <Update.h>

#define EEPROM_SIZE 64 // This can be smaller or larger, adjust to    //your needs as well as the chip capabilities
int wifi_ap_on = 0; // the address for the "flag"


// Wifi for Firmware Update and Configuration Server(s)
const char* host = "ESP32/8266";
char* ssid = "--- your desired ssid ---";
char* password = "--- your password ---";

// Define two types of Servers, they will however not run at the same // time
WebServer OTAserver(80); // OTA Server Port
WiFiServer ConfigServer(23); // Configuration Server Port

String header; // HTML requests will be stored in here

// HTML Pages for Firmware Updater
/*
 * These are the standard OTA examples that came with Arduino IDE
 * Modify and enhance as see fit, keeping in mind that my application
 * would not have access to the internet
 */

/*
 * Login page
 */
const char* loginIndex = 
 "<form name='loginForm'>"
    "<table width='20%' bgcolor='A09F9F' align='center'>"
        "<tr>"
            "<td colspan=2>"
                "<center><font size=4><b>ESP Firmware Update Page</b></font></center><br>"
                
                "<br>"
            "</td>"
            "<br>"
            "<br>"
        "</tr>"
        "<td>Username:</td>"
        "<td><input type='text' size=25 name='userid'><br></td>"
        "</tr>"
        "<br>"
        "<br>"
        "<tr>"
            "<td>Password:</td>"
            "<td><input type='Password' size=25 name='pwd'><br></td>"
            "<br>"
            "<br>"
        "</tr>"
        "<tr>"
            "<td><input type='submit' onclick='check(this.form)' value='Login'></td>"
        "</tr>"
    "</table>"
"</form>"
"<script>"
    "function check(form)"
    "{"
    "if(form.userid.value=='admin' && form.pwd.value=='admin')"
    "{"
    "window.open('/serverIndex')"
    "}"
    "else"
    "{"
    " alert('Error Password or Username')/*displays error message*/"
    "}"
    "}"
"</script>";

const char* serverIndex = "<form method='POST' action='/update' enctype='multipart/form-data'><input type='file' name='update'><input type='submit' value='Update'></form>";
// End HTML Pages 

// Other variables
int Btn = 0; // The PGM button, Usually connected to GPIO0
int wifi_ap = 0; // The Running MODE
int buttonState;
int buttonValue = 0;
int lastButtonState = LOW;
int buttoncount = 0;

void setup()
{
   Serial.begin(115200);
   EEPROM.begin(EEPROM_SIZE); initiate EEPROM
  /*
   * Upload the sketch via USB the first time, and let chip run for
   * a few seconds. We need to set the EEPROM location to a known
   * initial value. Then comment the following 3 lines, to prevent 
   * the chip from overwriting the EEPROM location on next startup
   */
  pinMode(Btn,INPUT);
  EEPROM.write(wifi_ap_on,0x00); // comment this line after first run
  EEPROM.commit();// comment this line after first run
  delay(50);// comment this line after first run
  wifi_ap = EEPROM.read(wifi_ap_on); // read EEPROM value into "flag"
  
  if (wifi_ap == 0x00) { 
   // This will be executed on normal startup
   // Place all your normal initialisation stuff here
   // For example other pin configurations and 
   // peripheral  initialisations
  } else if (wifi_ap == 0xFF) { // Firmware Update MODE
   // Setup for OTA Webserver.
   // I have used SoftAP mode, as internet would not
   // be available anyway.

    WiFi.softAP(ssid,password);
    IPAddress IP = WiFi.softAPIP();
    Serial.println("");
    Serial.print("Connected to ");
    Serial.println(ssid);
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP()); 
     
    if (!MDNS.begin(host)) { //http://esp32.local
        Serial.println("Error setting up MDNS responder!");
        while (1) {
        delay(1000);
      }
    }

    
    server.on("/", HTTP_GET, []() {
    server.sendHeader("Connection", "close");
    server.send(200, "text/html", loginIndex);
  });
  server.on("/serverIndex", HTTP_GET, []() {
    server.sendHeader("Connection", "close");
    server.send(200, "text/html", serverIndex);
  });
  /*handling uploading firmware file */
  server.on("/update", HTTP_POST, []() {
    server.sendHeader("Connection", "close");
    server.send(200, "text/plain", (Update.hasError()) ? "FAIL" : "OK");
    ESP.restart();
  }, []() {
    HTTPUpload& upload = server.upload();
    if (upload.status == UPLOAD_FILE_START) {
      Serial.printf("Update: %s\n", upload.filename.c_str());
      if (!Update.begin(UPDATE_SIZE_UNKNOWN)) { //start with max available size
        Update.printError(Serial);
      }
    } else if (upload.status == UPLOAD_FILE_WRITE) {
      /* flashing firmware to ESP*/
      if (Update.write(upload.buf, upload.currentSize) != upload.currentSize) {
        Update.printError(Serial);
      }
    } else if (upload.status == UPLOAD_FILE_END) {
      if (Update.end(true)) { //true to set the size to the current progress

/*
 * NOTE : We clear the EEPROM Flag after a sucessful Firmware Update
 * That way, the chip will stay in OTA mode on a failure.
 */
        EEPROM.write(wifi_ap_on,0x00);
        EEPROM.commit();
        delay(5);
        Serial.printf("Update Success: %u\nRebooting...\n", upload.totalSize);
      } else {
        Update.printError(Serial);
      }
    }
  });
    OTAserver.begin();
  } else if (wifi_ap == 0x0F) { // End of Mode 0xFF 

    //This is Configuration Mode
    //This code will normally not be executed,
    //As the device exits Config mode on restart, and
    //We dont write Mode 0x0F to EEPROM

  } // End of Mode 0x0F
} // End of Void Setup

void loop() 
{
  CountButton(); // Count Button Presses
  if (buttoncount == 5) { // Activate Configuration Mode
    buttoncount = 0;
    StartSoftAP(); // Start a SoftAP
  }
  if (wifi_ap == 0x0F) { // Code for the Config Server (TELNET Style)
       WiFiClient client = ConfigServer.available(); // Start Config
       if (client) {
          String currentLine = "";
          client.println();
          client.println("Telnet Server - Welcome");
          client.println();
          client.println("Press <Enter> to Login");
          
    while (client.connected()) {
      if (client.available()) {
       char c = client.read();
       if (c == '\n') {
        if (currentLine.length() == 0) {
           
        } else {
          // Process Commands
       if (currentLine == "Master123abc") {
        telnetLogin == true;
        client.println();
        client.println();
        client.println("****** MENU ******");
          client.println();
          client.println("MENU -  SHOW THIS MENU");
          client.println("RUF  -  Enable Firmware Update Mode");
          client.println("EXIT -  Exit Menu and RESTART");
          client.println();
          client.print("Command> ");
          currentLine = "";
       }
       // Show MENU
       if (currentLine == "MENU") {
        client.println();
        client.println();
        client.println("****** MENU ******");
          client.println();
          client.println("MENU -  SHOW THIS MENU");
          client.println("RUF  -  Enable Firmware Update Mode");
          client.println("EXIT -  Exit Menu and RESTART");
          client.println();
          client.print("Command> ");
          
       }
 
       // EXIT AND RESTART
       if (currentLine == "EXIT") {
        client.println();
        client.println("Restarting in 5 Seconds");
        delay(5000);
        client.stop();
        ESP.restart();
      }
      // Upgrade Frmware Mode
      if (currentLine == "RUF") {
          client.println();
          client.println("Enable Firmware Update Mode");
          client.print("Connect to SoftAP :");
          client.println(ssid);
          client.println("Browse to http://192.168.4.1 ");
          client.println("Login with Username admin, Password admin");
          EEPROM.write(wifi_ap_on,0xFF); // Set Flag in EEPROM
          EEPROM.commit();
          delay(5000);
          client.stop();
          ESP.restart(); // Restart Device
      }
      
       // End Process commands 
           
          currentLine = ""; 
        }
        
       } else if (c != '\r') {
        currentLine += c;
       }  
        
      } // End if client Available
    } // End While Client Connected
    client.stop();
   } // END Client
  } // END MODE 0x0F
  if (wifi_ap == 0xFF) {
    OTAserver.handleClient(); // Handle OTA Server
    delay(1);
  }
  if (wifi_ap == 0x00 )
    // Normal code goes here , to be executed every cycle
  {

} // End of Void Loop

void StartSoftAP() // Start SoftAP, for Configuration Server
{
  WiFi.mode(WIFI_OFF);
  WiFi.softAP(ssid,password);
  IPAddress IP = WiFi.softAPIP();
  ConfigServer.begin();  
  wifi_ap = 0x0F; // Set Flag to Config Mode
                  // Note that we dont write it in EEPROM
}

void CountButton() // Counts Button Presses, to enable Config Mode
{
  //int buttonState;
  //int buttonValue = 0;
  //int lastButtonState = LOW;
  //int buttoncount = 0;
  //unsigned long lastDebounceTime = 0;
  //int debounceDelay = 50;
  buttonValue = digitalRead(Btn);
  if (buttonState != lastButtonState) {
    if (buttonValue == LOW) {
      buttoncount++;
      if (buttoncount > 10) buttoncount = 0;
    }
  }
  delay(50);
  lastButtonState = buttonValue;
  // End Debouncing
  if (buttoncount == 5) digitalWrite(LED,HIGH);
}

This concludes a very long piece of code, question are welcome.
Thank you