In ChromeOS Flex, the Terminal is the entry point to Linux. Terminal settings include plenty of built-in fonts.
However, there is no simple way to install a Nerd Font or any custom font, and the Terminal cannot pick up fonts installed inside Linux either.
Here is a workaround to load a Nerd Font in the Terminal.
Nerd Fonts
First, go to Nerd Fonts and find the font you like.
Then copy the URL of the font file (*.ttf).
Load a nerd font in Terminal
Open the Terminal, press Ctrl+Shift+J inside Terminal and paste:

term_.prefs_.set('font-family', '"VictorMono Nerd Font", monospace');
term_.prefs_.set('user-css-text', '@font-face { font-family: "VictorMono Nerd Font"; src: url("https://raw.githubusercontent.com/ryanoasis/nerd-fonts/refs/heads/master/patched-fonts/VictorMono/VictorMonoNerdFont-Regular.ttf") format("truetype"); font-weight: normal; font-style: normal; } @font-face { font-family: "VictorMono Nerd Font"; src: url("https://raw.githubusercontent.com/ryanoasis/nerd-fonts/refs/heads/master/patched-fonts/VictorMono/VictorMonoNerdFont-Bold.ttf") format("truetype"); font-weight: bold; font-style: normal; } x-row { text-rendering: optimizeLegibility; font-variant-ligatures: normal; font-style: italic; }')
The terminal font updates immediately. A quick test confirms the Nerd Font is installed correctly.

Another way
Just install a terminal app and use the Nerd Font inside Linux — this is probably the easiest way. The screenshot below shows the Tilix terminal with JetBrainsMono Nerd Font.
