I've been trying to use ISF on stackblitz.
You can see my code here: https://stackblitz.com/edit/typescript-akptnb?file=index.ts
It seems like the Renderer works as it adds the shader to the canvas, but the image doesn't appear.
I tried to run this repository locally with the webcam started, but I'm getting the same result.
Screenshot:

I hope someone can help me as i really like this library and it's simplicity :)
All the best,
Emil