The patched Terminus Fonts for Powerline (renamed to Terminess) comes as bitmap fonts (pcf). After installing those fonts, you might still not see them appear as an option when choosing fonts. It could be because bitmap fonts support might be turned off on your system.
rm /etc/fonts/conf.d/70-no-bitmaps.conf sudo fc-cache -fv
or if you don’t have admin/root access then
cp /etc/fonts/conf.avail/70-force-bitmaps.conf to ~/.fonts.conf.d fc-cache -vf ~/.fonts