How do I download a Buffer that is returned from my server?

I have a Buffer that has the contains a PDF that I have not been able to successfully download. Every time I attempt to open the PDF, it fails to open. Here is the code I am using to download the file:

const content = new Blob(attach.content.data, { type: attach.contentType });

const encodedUri = window.URL.createObjectURL(content);
const link = document.createElement("a");

link.setAttribute("href", encodedUri);
link.setAttribute("download", attach.filename);

link.click();

Here is what the attach object looks like:

Here is what the Blob looks like:

Halp, plx!!!1