Arduino IDE can’t find ESP8266WiFi.h file

I am trying to use NOD MCU ESP8266WiFi with Arduino IDE

When I run this code:

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
char auth[] = "YourAuthToken";
char ssid[] = "YourNetworkName";
char pass[] = "YourPassword";

void setup(){
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);
}
void loop()
{
  Blynk.run();
}

I get the following error:

fatal error: ESP8266WiFi.h: No such file or directory

     #include <ESP8266WiFi.h>    
                         ^
compilation terminated.

exit status 1
Error compiling for board Arduino/Genuino Uno.