Goggle Font

You use a custom css file – https://support.printfriendly.com/button/developer-questions/custom-css-styles/ and within the custom css file you have to import the google font in the first line. Ex

@import url('https://fonts.googleapis.com/css?family=Supermercado+One');
body {
  font-family: 'Supermercado One', cursive;
}