You may need an appropriate loader to handle this file typeエラーの解消法

ERROR in ./src/index.scss
Module parse failed: Unexpected token (1:0)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders

npm install sass-loader sass webpack --save-dev

module.exports = {
  module: {
    rules: [
      {
        test: /\.scss$/,
        use: ["style-loader", "css-loader", "sass-loader"],
      },
    ],
  },
};

{
  test: /\.scss$/,
  include: path.resolve(__dirname, "src/styles"),
  use: ["style-loader", "css-loader", "sass-loader"],
}

npm install babel-loader @babel/core @babel/preset-env --save-dev

module.exports = {
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader",
          options: {
            presets: ["@babel/preset-env"],
          },
        },
      },
    ],
  },
};

rm -rf node_modules/.cache && npm run build