fonts
8 typefaces, four weights, or a .ttf you upload.
your page can be set in any of these 8: Inter, Poppins, Space Grotesk, Outfit, Plus Jakarta Sans, Playfair Display, JetBrains Mono, Bebas Neue. the font control is in appearance, colors and layout, next to a weight picker with regular, medium, semibold and bold.
your own font
pick custom and upload a .ttf. the file is checked to be a real truetype font before it is accepted, and it is served from your page rather than from a font site, so nothing about your visitors is handed to anyone else.
if the upload is later deleted, your page falls back to the default font rather than breaking.
only upload a font you are allowed to use. a lot of display fonts are free for personal pages and not for anything else, and that is between you and whoever made it.
still stuck? ask in the discord, someone will know.