Just a note about the use of character case with the WiFiUdp.h library – it can be troublesome especially if you wear trifocals
Note that in the “include” statement below, the header name is “WiFiUdp.h” and that in the creation of an instance the name used is “WiFiUDP” .
#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
const char* ssid = “";
const char* password = "”;
WiFiUDP Udp;
There may also be a library around somewhere labeled “WiFiUDP.h” or “WIFIUDP.h” that may cause additional confusion. I’m new to the ESP8266 and Arduino, so not sure about that though.