Install Tailwind CSS in React

npm install -D tailwindcss postcss autoprefixer
npx tailwindcss init -p

Add the paths to all of your template files in your tailwind.config.js file.

module.exports = {
  content: [
    "./src/**/*.{js,jsx,ts,tsx}",
  ],
  theme: {
    extend: {},
  },
  plugins: [],
}

Add the @tailwind directives for each of Tailwind’s layers to your ./src/index.css file.

@tailwind base;
@tailwind components;
@tailwind utilities;

Run your build process with npm run start.

npm run start

References
https://tailwindcss.com/docs/guides/create-react-app