I was following https://stunningui.design/installation and it seems like npm install tailwindcss clsx tailwind-merge doesnt to anything.
Also can you specify what file I'm supposed to add this code to?

 import { type ClassValue, clsx } from 'clsx'
import { twMerge } from 'tailwind-merge'

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs))
}

thank you.