Linking a local CSS file for the plugin UI in HTML

I want to use this UI library which was introduced in Figma’s official tutorial for plugin development.

I installed this library with NPM.
But I can’t link the CSS file.

Here’s my html code.

<link rel="stylesheet" href="node_modules/figma-plugin-ds/dist/figma-plugin-ds.css">

The path for the href is not wrong, because VS Code can follow the link.
I tried to put the link tag in head tag, but it didn’t work.

Plus, if I use CDN for the CSS like this, it works.


But I don’t want to use this, because of the delay of style adjustment. It makes the UI blink.

What am I doing wrong? I want to link this CSS file in my local!
Thank you.