Пример загрузки шрифта на JavaScript

var font = new FontFace('Awesome Font', 'url(/fonts/awesome.woff2)', {
  style: 'normal', 
  unicodeRange: 'U+000-5FF', 
  weight: '400'
});
font.load(); // don't wait for render tree, initiate immediate fetch!

font
  .ready()
  .then(() => {
    // apply the font (which may rerender text and cause a page reflow)
    // once the font has finished downloading
    // document.fonts.add(font);
    // document.body.style.fontFamily = "Awesome Font, serif";
    // ...
});