Change Top Logo on the Left

You need to use the full pathname of the logo file

            header: {
                title: "XYZ",
                image: "/home/username/.node-red/static/logo.png"
            },

https://discourse.nodered.org/t/custom-div-banner-above-the-editor/52284

Edit - I just checked and it does work with the full pathname, the value of httpStatic is not used for this.