I wanted to make a script in my Godot project autoload, so I added it to the Project Settings > Globals > Autoload.

Autoload settings

But when I ran my project the value was always nil.

Autoload script nil

According to the documentation, a node should automatically be created for this script, but that does not seem to happen when I check the remote scene tree during the run.

Scene tree without autoload

When I updated the autoloaded script to extend Node it worked.

extends Node

var amount: int = 0
...
Scene tree autoload