ESP8266WiFi.h connect to wifi with ssid, username and password code example

Example 1: nodemcu router code

#include <ESP8266WiFi.h>

const char* ssid = "******"; 
const char* password = "******";

IPAddress staticIP(192,168,1,22); 
IPAddress gateway(192,168,1,9); 
IPAddress subnet (255,255,255,0);

void setup(void) {
    Serial.begin(9600); 
    Serial.println();

    Serial.printf("Connecting to Xs \n", ssid); 
    WiFi.begin(ssid, password); 
    WiFi.config(staticIP, gateway, subnet);

    while (WiFi.status() != WL_CONNECTED) {
        delay(500); 
        Serial.print("."); 
    }

    Serial.println();
    Serial.print("Connected, IP address: "); 
    Serial.println(WiFi.localIP());
}
void loop() {}

Example 2: how to connect esp8266 to access point with known ip address

#include <ESP8266WiFi.h>        // Include the Wi-Fi library

const char* ssid     = "SSID";         // The SSID (name) of the Wi-Fi network you want to connect to
const char* password = "PASSWORD";     // The password of the Wi-Fi network

void setup() {
  Serial.begin(115200);         // Start the Serial communication to send messages to the computer
  delay(10);
  Serial.println('\n');
  
  WiFi.begin(ssid, password);             // Connect to the network
  Serial.print("Connecting to ");
  Serial.print(ssid); Serial.println(" ...");

  int i = 0;
  while (WiFi.status() != WL_CONNECTED) { // Wait for the Wi-Fi to connect
    delay(1000);
    Serial.print(++i); Serial.print(' ');
  }

  Serial.println('\n');
  Serial.println("Connection established!");  
  Serial.print("IP address:\t");
  Serial.println(WiFi.localIP());         // Send the IP address of the ESP8266 to the computer
}

void loop() { }