Not having specific information about 'Carver based on a true story' makes it tough to point out the exact place to find it. If it's a book, you might want to check with smaller, niche bookshops that deal with true - story or biographical works. They may have it in stock or be able to order it for you. In terms of a movie, if it has been made, it could be in the archives of local film institutions or in the collections of enthusiasts who are into true - story movies. You could also keep an eye on online forums dedicated to media discovery to see if anyone has any leads on it.
Since I don't know much about this 'Carver based on a true story', it's a bit hard to say exactly where to find it. If it's a relatively unknown work, it might be available in second - hand bookstores or from independent publishers. For the movie version, if it exists, it could be at film festivals, especially those that focus on independent or true - story - based films. You could also try reaching out to film clubs or cinephile communities to see if they know of its availability.