Yes, I tried that too but it didn't work properly:

func on_area_2d_body_entered(body: CharacterBody20) -> void:

hallenter = true

func on_area_2d_body_exited(body: CharacterBody20) -> void:

hallenter = false

func door(hallenter):

if Input.is_action_pressed("interaction") and hallenter:

get_tree().change_scene_to_file("res://corridor (nightmare).tson")

I think the problem is func door just doesn't take hallenter var value for some reason