how do you write to an author?

answers1: Most writers have a website with a contact section. You
might get a home address or you might get an email address.
answers2: The author's website would be the obvious place to start. If
that doesn't say, you can usually write to the author's publisher, who
will forward letters (yes, real letters written on paper - not email).
Phone the publisher first to ask how they want you to do it.
Obviously, it will be a while before you get a response from the
author, if you get one at all.
answers3: who's the author ?
answers4: Most authors have a website with a way to contact them.
Have you tried that? Who's the author?