Here's a super ugly workaround for client-components, until something better is proposed (I hate this too, but it works):

npm i pdfjs-dist

Edit 1: A hook might be better for reusability:

Create Your Hook

"use client";
import {useEffect} from "react";
import * as PDFJS from "pdfjs-dist/types/src/pdf";

export const usePDFJS = (onLoad: (pdfjs: typeof PDFJS) => Promise<void>, deps: (string | number | boolean | undefined | null)[] = []) => {
  
  const [pdfjs, setPDFJS] = useState<typeof PDFJS>(null);
  
  // load the library once on mount (the webpack import automatically sets-up the worker)
  useEffect(() => {
    import("pdfjs-dist/webpack.mjs").then(setPDFJS)
  }, []);

  // execute the callback function whenever PDFJS loads (or a custom dependency-array updates)
  useEffect(() => {
    if(!pdfjs) return;
    (async () => await onLoad(pdfjs))();
  }, [ pdfjs, ...deps ]);
}

Typescript Fix

Your compiler might complain about a typescript issue; if so, I just added an index.d.ts (note the .d.ts) at the same level as my hook:

declare module 'pdfjs-dist/webpack.mjs' { export * from 'pdfjs-dist' }

Use Your Hook

"use client";
import {usePDFJS} from "...";


export default function Page() {
  usePDFJS(async (pdfjs) => {
    console.log(pdfjs)
  })
}

It's too late to reply to this questions but let me add the solution that worked for me for those who will wish to implement the some issue.

This is the code that will work fine

// Install the latest version of pdf.js via npm i pdfjs-dist
const pdfjsLib = require("pdfjs-dist/legacy/build/pdf.js");


  let pdf_path = "{RELATIVE_PATH_TO_YOUR_FILE}/sample.pdf";


   async function getContent(src: any){
    const doc = await pdfjsLib.getDocument(src).promise;
    const page = await doc.getPage(1);
    const strings: any = await page.getTextContent();
    let ITEMS_STRINGS = strings.items.map((item: any) => item.str);
    let PDF_STRINGS: string = ITEMS_STRINGS.join(" ");
    return PDF_STRINGS;
  }

  console.log(await getContent(`${pdf_path}`));

This will work fine