HI! Of course you can
If you have purchased, personal or libre fonts that are not included in the catalog provided by Penpot, you can upload them from your computer and use them across the files of a team.
It’s very easy to do! To use at Penpot a font that you have at your local machine, you need to upload it first to the Penpot team where you want it.
You can find the “Fonts” section in the dashboard menu, at the left sidebar.
Here yo have more info about custom fonts in Penpot.