const postscribeScript = require('postscribe-script');

// add a `document.write(...)` ad script
postscribeScript('#ad', 'https://example.com/document-writer.js').then(() => {
  // script was loaded and evaluated, and presumably wrote something inside #ad
});

// load jQuery dynamically
postscribeScript('https://code.jquery.com/jquery-git.min.js').then(() => {
  // script was loaded and evaluated, we can use whatever it exports
  $('body').fadeIn();
});

// something more realistic
postscribeScript('https://api-maps.yandex.ru/2.1/')
  .then(() => ymaps.ready())
  .then(() => {
    const map = new ymaps.Map('map', {
      center: [55.751574, 37.573856],
      zoom: 9
    });
  });