Carson Burton Zac Efron is heading to Vietnam in the first trailer for “The Greatest Beer Run Ever.”Apple TV+ dropped the trailer for its upcoming true-life war comedy starring Efron, Russell Crowe and Bill Murray. The film, which is based on a true story, follows Efron as John “Chickie” Donohue. Set in 1967, Donohue leaves New York to track down his army friends in Vietnam and share a few beers with them to show that they have support from the American people.