https://arduino-esp8266.readthedocs.io/en/latest/esp8266wifi/soft-access-point-class.html
#include <ESP8266WiFi.h>
IPAddress local_IP(192,168,4,22);
IPAddress gateway(192,168,4,9);
IPAddress subnet(255,255,255,0);
void setup()
{
Serial.begin(115200);
Serial.println()...