How do i add a custom font to squarespace?

Hey!

I am trying to upload a custom font to our site. This is the custom css we have put in, but it is not showing up. Any help?

@font-face { font-family: 'cheddarjack'; src: url('https://static1.squarespace.com/static/58d94a3b6b8f5bf8254dece2/t/598f6ce64c0dbfafe1ecf031/1502571750536/cheddar+jack.ttf');}h1 { font-family: cheddarjack; font-size: 30px; font-weight: bold; color: #444444;}