converting int to str

I feel like I'm making a dumb mistake. This code worked in a previous version of godot, but in the 4.0 I get an error saying 'Invalid type 'int'. Cannot convert arguement 1 from Stringname to String'
Essentially I'm trying to make a hitbox to transition you to the next level, instead of making a bunch of unique ones.

func _on_area_2d_body_entered(body):
	if body.name == "player":
		#print("res://world_" + str(int(get_tree().current_scene.name) + 1) + ".tscn")
		get_tree().change_scene_to_file("res://world_" + str(int(get_tree().current_scene.name) + 1) + ".tscn")