I am trying to append string to existing document in JS, but i did not find proper way of doing it without library like docx. Is there a way to achieve this by for example fs.appendFile function?

My code:

var fs = require("fs");

fs.appendFile("test.docx", " This is my text.", "utf8", function (err) {
  if (err) throw err;
  console.log("Updated!");
});