The recommended way to use the Material Icons font is by linking to the web font hosted on Google Fonts:

<!-- https://material.io/resources/icons/?style=baseline -->
<link href="https://fonts.googleapis.com/css2?family=Material+Icons"
      rel="stylesheet">

<!-- https://material.io/resources/icons/?style=outline -->
<link href="https://fonts.googleapis.com/css2?family=Material+Icons+Outlined"
      rel="stylesheet">

<!-- https://material.io/resources/icons/?style=round -->
<link href="https://fonts.googleapis.com/css2?family=Material+Icons+Round"
      rel="stylesheet">

<!-- https://material.io/resources/icons/?style=sharp -->
<link href="https://fonts.googleapis.com/css2?family=Material+Icons+Sharp"
      rel="stylesheet">