Help with Custom Rectangle tool button

I checkded the console there are no 404s,
Heres’ the code I use to load PDF.Js Express,
this.webViewerInstance = WebViewer(
{
path: “…/lib/public”,
//initialDoc: “…/files/webviewer-demo-annotated.pdf”,
config: “…/assets/myConfig.js”,
},
this.viewer.nativeElement
);
Here’s the folder structure for lib folder
image