Can you share the amazon link you'r'e using? We verify the format of the link and it's rejecting what you provided.
Sorry, I've already solved and forgot to delete this post.
I had to use an amazon.com link instead of amazon.it one.
I got a similar error, but changed ".co.uk" to ".com" and it worked. Although, the error message should be "use an Amazon.com" URL instead of "use a Google Play" one.
