camera.add_script(SmoothFollow()) doesn’t work. here’s my code:

from ursina import *

class Player(Entity):
    def __init__(self):
        super(Player, self).__init__(
            model='quad',
            scale=1,
            parent='scene',
            color=color.green
        )

        self.speed = 5



    def update(self):
        move_direction = Vec2(held_keys['d']-held_keys['a'], held_keys['w']-held_keys['s']).normalized()
        player.position += move_direction * player.speed * time.dt

app = Ursina()

player = Player()
camera.orthographic = True
camera.fov = 20
camera.add_script(SmoothFollow(target=player, speed=8, offset=[0, 0, -4]))

app.run()

i tried this script on the other entity, not camera and it works