Why i cannot add png image to pdf using pdf-lib?

Question

I tried to add png image in nest.js using pdf-lib

import { PDFDocument } from 'pdf-lib';
import * as fs from 'fs';

const existingPdf = await fs.readFileSync(
      './agreements/1431993ded73f6a0be5653a3e3fc680f.pdf',
    );
    const pdfDoc = await PDFDocument.load(existingPdf);
    const pdfPage = await pdfDoc.getPage(1);
    

    const pdfImage = await pdfDoc.embedPng(getAddressDto.signBase64);
    pdfPage.drawImage(pdfImage, {
      x: 10,
      y: 10,
      width: 15,
      height: 40,
    });
    return await pdfDoc.save();

my png image in base64 format. there if nothing in console and there is no image in file

also i tried to add new page, but it didn't work too