You can’t just copy and paste code from the Git example page when it is to do with connection configuration.
Since you are using XAMPP you will need the code to be:
$b1 = (new TADFactory(['ip'=>'127.0.0.1']))->get_instance();
127.0.0.1 is an alias for localhost which is what you will be connecting to on your local machine. Naturally, this will change if you put this code into production as the IP will no longer be local.
I have never used the TAD library, however, based on the error message you supplied, the following should fix your problem. For now…
Please don’t copy and paste, it’s best to learn what the code does rather than take it and use it and move on.