How to make the arduino triggered to send alert notification by using Blynk

Hello i have trying to use the blynk for the arduino to be able to triggered to send alert notification by using Blynk. But everytime i try to run the codes it gives me same error about the library on #include<Esp8266Wifi.h>

you might be using the wrong board type with your code?

try this

https://examples.blynk.cc/?board=Arduino%20Uno&shield=Arduino%20WiFi%20Shield&example=Widgets%2FPushNotification%2FPushNotification_Interval

Can you suggest me a link where i can download this library please?
#include <BlynkSimpleWifi.h>

Install the whole library as directed… if you are missing something then the Library is not properly installed.