Trying to add a new non-Google font to Upfront

Hi! I'm working on a site using a theme I created via Upfront. I'm trying to install a custom font, I created it via @font-face using the instructions I found here - https://premium.wpmudev.org/forums/topic/upfront-builder-issue-custom-font-implementation-not-google-fonts - but it's not working right. I feel like I'm close but missing something small.