Inside of the autonomous node, you can add variables under the Variable access field and check mark the box next to it that says "allow write access" so it can edit it https://cdn.discordapp.com/attachments/1108396291060408352/1478237858715271231/image.png?ex=69a7abc9&is=69a65a49&hm=6ea6eb5650546a5068f8ffd105f70cb604f30ae3f362765e2204306972bfce85&