How to download Fira Mono Regular and Medium (for bold) patched nerd font:
FONT_TARGET_DIR="${HOME}/.fonts/"
cd ~/Downloads
curl -fsL https://github.com/ryanoasis/nerd-fonts/releases/download/v3.4.0/FiraMono.tar.xz
mkdir FiraMono
mv FiraMono.tar.xz FiraMono/
cd FiraMono
tar xvzf FiraMono.tar.xz
mkdir -p $FONT_TARGET_DIR
cp FiraMonoNerdFont-Regular.otf FiraMonoNerdFont-Medium.otf FiraMonoNerdFont-Bold.otf $FONT_TARGET_DIR
fc-cache -f
cd ~/Downloads
trash-put FiraMonoThen in terminal configuration, e.g. in kitty.conf:
font_family FiraMono Nerd Font
bold_font FiraMono Nerd Font Medium