Download in JavaScript

download.js

function download(filename, text) {
  // create link element
  const element = document.createElement('a')
  
  // set link href to our text
  element.setAttribute('href', `data:text/plain;charset=utf-8,${encodeURIComponent(text)}`)
  
  // set attribute download
  element.setAttribute('download', filename)
  
  // make element invisible
  element.style.display = 'none'
  
  // add element to the DOM
  document.body.appendChild(element)
  
  // simulate click
  element.click()
  
  // and remove element from the DOM
  document.body.removeChild(element)
}