unable to get Whats app regisrtation code using WART

I am making application using C# t o send messages on whats App,

( taking help from his video "https://www.youtube.com/watch?v=4i4G7GBSgnI", )

Problem: unable to get what's registration code using WART. ,its giving me below

Solution Required: How to remove this error to get registration code to get password which I will use in my code.

Note:I am giving number using country code like this 00923003533768

Kindly help me on this to get what's app registration code

Thanks