Drew Van Acker is known as the Jason DiLaurentis actor in Pretty Little Liars, but he wasn't the first actor cast in the role. Parker Bagley was initially cast as Jason, appearing in Pretty Little Liars season 1 before Van Acker took over. Created by I. Marlene King and inspired by the books by Sara Shepard, the series centers on the disappearance of Alison DiLaurentis (Sasha Pieterse) and the fallout that ensues among her group of friends when they start to be harassed by a Pretty Little Liars' villain "A." Jason is Alison's older brother who is thrust into the drama surrounding his sister and friends. With the twists in the show, he's also eventually revealed as the half-brother of Alison's friend Spencer Hastings (Troian Bellisario).

https://screenrant.com/pretty-little-liars-jason-parker-bagley-recast-reason/