How to automatically prefix scss with autoprefix in vite

I have installed postcss and autoprefix in in npm with

npm i autoprefixer && npm i postcss

and my vite.config.js file looks like this:

import { defineConfig } from 'vite';
import laravel from 'laravel-vite-plugin';
import react from '@vitejs/plugin-react'
import autoprefixer from 'autoprefixer';

export default defineConfig({
    plugins: [
        react(),
        laravel({
            input: [
                'resources/sass/app.scss',
                'resources/js/index.tsx',
            ],
            refresh: true,
            postcss: {
                plugins: [
                    autoprefixer(),
                ]
            },
        }),
    ],
});

But when I run npm run dev or npm run build the css doesn`t seem to be prefixed. How can I fix this? I have also tried to create a postcss.config.js file like this:

module.exports = {
    plugins: {
        autoprefixer: {}
    }
}

But this also doesn`t work. I have "browserlists": [ "defaults" ] in my package.json