Google Fonts CDN ссылка
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto"/>
Grumpy Grebe
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto"/>@import url(https://fonts.googleapis.com/css?family=Open+Sans);
body{
font-family: 'Open Sans',serif;
}<!-- To Add Montserrat font or any font as such -->
<!-- Go to https://fonts.google.com browse the font you like here, Montserrat-->
<!-- On the right click embbed and get the link similar to one given below-->
<link href="https://fonts.googleapis.com/css2?family=Montserrat&display=swap" rel="stylesheet">
<!-- add this ^ link inside your <head> tag i.e. before </head> -->
<!-- In css you can specify the font family as -->
font-family: "Montserrat", sans-serif;<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Open+Sans:300,400,600,700&lang=en" /><link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Montserrat|Ubuntu"/>