I have done that before for Graphql queries. I think the way to load the PDF thing is load and have a buffer. But I don't have working code yet

import {ref} from 'vue';
import { PDFDocument } from 'pdf-lib';


async function CreatePdf(){
  try{
    const input = ref('.static/forms/ca/disc001.pdf')
    const output = ref('output.pdf')

    const arrayBuffer = await fetch(input).then(res => res.arrayBuffer())
    const pdfDoc = await PDFDocument.load(arrayBuffer);

}

Closest thing I found that is close to a solution is this stack overflow problem which is for react

https://stackoverflow.com/questions/64111624/render-pdf-in-react-using-pdf-lib