Why is the name of a package still undefined after importing it from node module in SFC?

[ssppest]

Why is the name of a package still undefined after importing it from node module in SFC?
code looks like:

<template>
  <div>
    this is pdf
  </div>
</template>

<script setup>
import * as pdfjsLib from "pdfjs-dist/legacy/build/pdf.js"
console.log(window);
console.log(window.pdfjsLib);
console.log(pdfjsLib);
</script>

The window object contains pdfjsLib, but the variable pdfjsLib is still undefined