In case anyone didn’t know, you can actually “climb” onto the door in trailer on Firing Range

Takes some practice but once you know how, it's easy. And it almost always catches the opponents off guard Imao.

Just align your crosshair between the door and the wooden board, look up and spam jump until your character does a "double jump" animation and you should be stuck between the door and the wall. You should be able to climb up on the door from there.