Cytron WiFi Shield - ESP is not responding

Hi, I did followed this one video from Cytron on Youtube (https://www.youtube.com/watch?v=iYTbS3RKZBQ)
followed exactly the same as the video.
I used Arduino UNO, Cytron Wifi Shield and the example code ESP8266_Shield.ino
Here is the response of the Serial Monitor:
[19]
___ __ __
/ _ )/ /_ _____ / /__
/ _ / / // / _ \/ '_/
/____/_/\_, /_//_/_/\_\
/___/ v0.5.8 on Arduino Uno
[609] Connecting to my@unifi
[1623] ESP is not responding
Please do respond ASAP.
followed exactly the same as the video.
I used Arduino UNO, Cytron Wifi Shield and the example code ESP8266_Shield.ino
Here is the response of the Serial Monitor:
[19]
___ __ __
/ _ )/ /_ _____ / /__
/ _ / / // / _ \/ '_/
/____/_/\_, /_//_/_/\_\
/___/ v0.5.8 on Arduino Uno
[609] Connecting to my@unifi
[1623] ESP is not responding
Please do respond ASAP.