If anyone wants to change the name (SSID) of the Access Point (AP) that appears (with the IP address 192.168.4.1) about wifimanager HOT 12 CLOSED

  // not connected start configportal
  bool res = startConfigPortal(apName, apPassword);

/**
 * get config portal AP SSID
 * @since 0.0.1
 * @access public
 * @return String the configportal ap name
 */
String WiFiManager::getConfigPortalSSID() {
  return _apName;
}

char const * portal_SSID = {"DEVICE1"};
char const * portal_PASSWORD = {"12345678"}; // Need >= 8 chars

wm.autoConnect(portal_SSID, portal_PASSWORD);
wm.startConfigPortal(portal_SSID, portal_PASSWORD);

    // handle timed out
    if(millis() > _configPortalStart + _configPortalTimeout){
      #ifdef WM_DEBUG_LEVEL
      DEBUG_WM(F("config portal has timed out"));
      #endif
      return true; // timeout bail, else do debug logging
    } 

      // log timeout time remaining every 30s
      if((millis() - timer) > logintvl){
        timer = millis();
        #ifdef WM_DEBUG_LEVEL
        DEBUG_WM(WM_DEBUG_VERBOSE,F("Portal Timeout In"),(String)((_configPortalStart + _configPortalTimeout-millis())/1000) + (String)F(" seconds"));
        #endif
      }

#include <Arduino.h>

/**
 * OnDemandNonBlocking.ino
 * example of running the webportal or configportal manually and non blocking
 * trigger pin will start a webportal for 120 seconds then turn it off.
 * startAP = true will start both the configportal AP and webportal
 */
#include <WiFiManager.h> // https://github.com/tzapu/WiFiManager

// include MDNS
#ifdef ESP8266
#include <ESP8266mDNS.h>
#elif defined(ESP32)
#include <ESPmDNS.h>
#endif

// select which pin will trigger the configuration portal when set to LOW
#define TRIGGER_PIN 0 // ESP8266 GPIO0 (NodeMCU D3)

#define LED_BUILTIN_D4 2 // ESP8266 GPIO2 (NodeMCU D4)

char const *portal_SSID = {"DEVICE1"};
char const *portal_PASSWORD = {"12345678"}; // Need >= 8 chars

WiFiManager wm;

unsigned int timeout = 120; // seconds to run for
unsigned int startTime = millis();
//bool portalRunning = false;
bool startAP = true; // start AP and webserver if true, else start only webserver

uint32_t millis1 = 0;
uint32_t millis2 = 0;

void doWiFiManager();

void setup()
{
  WiFi.mode(WIFI_STA); // explicitly set mode, esp defaults to STA+AP
  // put your setup code here, to run once
  Serial.begin(115200);
  Serial.setDebugOutput(true);
  delay(1000);
  Serial.println("\n Starting");

  pinMode(TRIGGER_PIN, INPUT_PULLUP);
  pinMode(LED_BUILTIN_D4, OUTPUT);
  digitalWrite(LED_BUILTIN_D4, HIGH);

  wm.setConfigPortalTimeout(timeout);

  // wm.resetSettings();
  wm.setHostname("MDNSEXAMPLE");
  // wm.setEnableConfigPortal(false);
  wm.setConfigPortalBlocking(false);
  // wm.autoConnect();

  wm.autoConnect(portal_SSID, portal_PASSWORD);
}

void loop()
{
#ifdef ESP8266
  MDNS.update();
#endif
  doWiFiManager();
  // put your main code here, to run repeatedly:

  if (wm.getConfigPortalActive() == true)
  {
    if ((millis() - millis2) > 500)
    {
      millis2 = millis();

      digitalWrite(LED_BUILTIN_D4, !digitalRead(LED_BUILTIN_D4));
    }
  } else {
    if ((millis() - millis2) > 5000)
    {
      millis2 = millis();
    }

    if (((millis() - millis2) < 500))
    {
      digitalWrite(LED_BUILTIN_D4, LOW);
    } else if (((millis() - millis2) > 500) && ((millis() - millis2) < 1000))
    {
      digitalWrite(LED_BUILTIN_D4, HIGH);
    }
  }
}

void doWiFiManager()
{
  // is auto timeout portal running
  if (wm.getConfigPortalActive()) //portalRunning
  {
    wm.process(); // do processing

    // check for timeout
    if ((millis() - startTime) > (timeout * 1000))
    {
      Serial.println("portaltimeout");
      //portalRunning = false;
      if (startAP)
      {
        wm.stopConfigPortal();
      }
      else
      {
        wm.stopWebPortal();
      }
    }
  }

  // is configuration portal requested?
  if (digitalRead(TRIGGER_PIN) == LOW && (!wm.getConfigPortalActive())) // !portalRunning
  {
    // Minimum button press time to activate the portal
    if ((millis() - millis1) > 15000)
    {
      digitalWrite(LED_BUILTIN_D4, HIGH);

      // Wait for user to release button
      while(digitalRead(TRIGGER_PIN) == LOW) {
        yield();
      }

      if (startAP)
      {
        Serial.println("Button Pressed, Starting Config Portal");
        wm.resetSettings();
        wm.setConfigPortalBlocking(false);
        wm.startConfigPortal(portal_SSID, portal_PASSWORD);
      }
      else
      {
        Serial.println("Button Pressed, Starting Web Portal");
        wm.startWebPortal();
      }
      //portalRunning = true;
      startTime = millis();
    }
    else
    {
      digitalWrite(LED_BUILTIN_D4, LOW);
    }
  }
  else
  {
    millis1 = millis();
  }
}