I wasn’t able to find information about how implement this library in nest js beacuse documentation is incomplete so am letting this here, you need first npm install pdfmake –save and npm install @types/pdfmake –save-dev then this code is working for me using node 20

import { Injectable } from '@nestjs/common';
import pdfFonts from 'pdfmake/build/vfs_fonts';
import * as fs from 'fs';
import pdfMake from 'pdfmake/build/pdfmake';
import { TDocumentDefinitions } from 'pdfmake/interfaces';

@Injectable()
export class AppService {
  constructor() {
    (pdfMake as any).vfs = pdfFonts.pdfMake.vfs;
  }
  getHello() {
    const dd: TDocumentDefinitions = {
      content: [
        'First paragraph',
        'Another paragraph, this time a little bit longer to make sure, this line will be divided into at least two lines',
        {
          text: 'This paragraph will have a bigger font',
          fontSize: 15,
          color: 'blue',
        },
        {
          columns: [
            {
              text: 'This is a column',
            },
            {
              text: 'Another column',
            },
          ],
        },
        { text: 'Tables', style: 'header' },
        'Official documentation is in progress, this document is just a glimpse of what is possible with pdfmake and its layout engine.',
        {
          text: 'A simple table (no headers, no width specified, no spans, no styling)',
          style: 'subheader',
        },
        'The following table has nothing more than a body array',
        {
          style: 'tableExample',
          table: {
            body: [
              ['Column 1', 'Column 2', 'Column 3'],
              ['One value goes here', 'Another one here', 'OK?'],
            ],
          },
        },
      ],
    };

    const pdfDoc = pdfMake.createPdf(dd);

    pdfDoc.getBuffer((buffer) => {
      fs.writeFileSync('pdf/output.pdf', buffer);
      console.log('PDF saved successfully');
    });

    return 'Hello World!';
  }
}

Just to let others the way to implement is a readdly good library to generate pdfs from backend