Install daisyUI for PostCSS

1. Install

Initialize a new Node project in the current directory using npm init -y if it's not a Node project already.

Install PostCSS, Tailwind CSS, and daisyUI

npm i postcss postcss-cli tailwindcss @tailwindcss/postcss daisyui@latest

2. Add Tailwind CSS and daisyUI

Create a postcss.config.mjs file and add Tailwind CSS to it

const config = {
  plugins: {
    '@tailwindcss/postcss': {},
  },
};
export default config;

Add Tailwind CSS and daisyUI to your CSS file.
Address your HTML and other markup files in the source function.

@import "tailwindcss";
@plugin "daisyui";

3. Build CSS

Add a script to your package.json to build the CSS.

{
  "scripts": {
    "build:css": "postcss app.css -o public/output.css"
  },
}

Run the script to build the CSS file

npm run build:css

This command creates a public/output.css file with the compiled CSS. You can link this file to your HTML file.

<link href="./output.css" rel="stylesheet">

Now you can use daisyUI class names!