Press ctrl+shift+j in the terminal, then paste the below.
term_.prefs_.set('font-family', 'JetBrains Mono Nerd Font, monospace');
term_.prefs_.set('user-css-text', '@font-face {font-family: "JetBrains Mono Nerd Font"; src: url("https://raw.githubusercontent.com/ryanoasis/nerd-fonts/master/patched-fonts/JetBrainsMono/Ligatures/Regular/complete/JetBrains%20Mono%20Regular%20Nerd%20Font%20Complete.ttf"); font-weight: normal; font-style: normal;} x-row {text-rendering: optimizeLegibility;font-variant-ligatures: normal;}')
See https://gist.github.com/izzqz/af36c5bbde67ffff0f7614cf738d75a5 for details.
Plus, you can change font size.
term_.prefs_.set('font-size', 15)
This is from https://chromium.googlesource.com/apps/libapps/+/HEAD/nassh/docs/FAQ.md#How-do-I-use-web-fonts
p.s. It still doesn’t render all the icons, e.g,. vim-tree in nvim. I don’t know answer for that.