vue3 で laravelmix element plus をインストール

element plus をインスコ

npm install element-plus --save

webpackに追加

webpack.mix.js

mix.webpackConfig(
{
    module:
    {
        rules:
        [
            {
                test: /\.mjs$/,
                resolve: { fullySpecified: false },
                include: /node_modules/,
                type: "javascript/auto"
            }
        ]
    },
}
);

絶対パスで読み込みましょう

app.js

import ElementPlus from '/var/www/html/your/node_modules/element-plus/'
import '/var/www/html/your/node_modules/element-plus/dist/index.css'

app.use(ElementPlus)
app.mount('#app');

以上