Fonts
Omarchy uses JetBrainsMono Nerd Font as both the terminal and system font by default.

You can change this through the Style > Font menu in the Omarchy menu (Super + Space). That sets the monospace font everywhere: the terminal, the bar, and anything else that asks for it.
You can install other popular programming fonts via Install > Style > Font in the Omarchy menu: Cascadia Mono, Meslo LG Mono, Fira Code, Victor Code, Bitstream Vera Mono, and Iosevka are all one click away, in their Nerd Font versions so the glyphs in the bar and terminal keep working. After installing one, pick it under Style > Font.