Impossible to get the API key for following the book outside USA

I’m just started with the book, but to be able to follow I have to get an API key from petfinder. But that site only accepts sings up if you live in the USA, Canada or Mexico. Furthermore, I managed to sing up after searching for a postal code from Canada (not very nice, I know, but…) and now the form to get the API key asks me for an URL from my app, which I obviously don’t have.