I am trying to create a PDF file from Base64 with the following code:

const stream = require('stream');
  
// Creating a stream and creating 
// a write function
const writable = new stream.Writable({
  
  // Write function with its 
  // parameters
  write: function(chunk, encoding, next) {
  
    // Converting the chunk of
    // data to string
    console.log(chunk.toString());
    next();
  }
});
  

const base64 = require('base64topdf');
const fs = require('fs');
var pdfBase64string = "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"
var bitmap = new Buffer.from(pdfBase64string, 'base64');

// Writing data
var x = writable.setDefaultEncoding("latin1");
writable.write(bitmap);

I run the code with the command node generatepdf.js > test.pdf

The pdf file is created, but the content is blank. How to generate it correctly ?