uploading using form-data a remote file

Question

in my node application I want to use FormData to upload a remote image. To do this I'm trying the following

  const form = new FormData();
  ...
  const result = await fetch(image);
  form.append("file", result.body);
  ...

This is generating the following error:

TypeError: source.on is not a function

I'm wondering what I have to pass to form.append to make it work. I tried also using result.blob() without any luck. Any help appreciated.