Warnings during webpack Hot UPDAT

error

WARNING in configuration
The "mode" option has not been set. Set "mode" option to "development" or "production" to enable defaults for this environment.

WARNING in asset size limit: The following asset(s) exceed the recommended size limit (244 KiB).
This can impact web performance.
Assets:
  print.0989fjs (348 KiB)
  vendors.0989fjs (357 KiB)
  index.0989fjs (885 KiB)

WARNING in entrypoint size limit: The following entrypoint(s) combined asset size exceeds the recommended limit (244 KiB). This can impact web performance.
Entrypoints:
  index (885 KiB)
      index.0989fjs
  vendors (357 KiB)
      vendors.0989fjs
  print (348 KiB)
      print.0989fjs


WARNING in webpack performance recommendations:
You can limit the size of your bundles by using import() or require.ensure to lazy load some parts of your application.
For more info visit https://webpack.js.org/guides/code-splitting/

this is the configuration file

const webpack = require("webpack");

module.exports = {
    // devtool: "inline-source-map",
    devServer: {
        contentBase: "./dist",
        compress:true,
        port:9000,
        host:"127.0.0.1",
        hot: true, 
       
    },
    entry: {
        index: "./src/index.js",
        vendors: ["react"],
        
    },

    plugins: [
        new CleanWebpackPlugin(["dist"]),
        new HTMLWebpackPlugin({
            title: "Code Splitting"
        }),
        new webpack.NamedModulesPlugin(),
        new webpack.HotModuleReplacementPlugin()

    
    ],
    
    output: {
        filename: "[name].[hash:5]js",
        path: path.resolve(__dirname, "dist"),
        hotUpdateChunkFilename: "hot/hot-update.js",  //js
        hotUpdateMainFilename: "hot/hot-update.json", //json 
    }
};

what should I do with it

// devtool: 'inline-source-map', mode: "development", // devServer: { contentBase: './dist', compress:true, port:9000, host:'127.0.0.1', hot: true, }, entry: { index: './src/index.js', vendors: ['react'], }, plugins: [ new CleanWebpackPlugin(['dist']), new HTMLWebpackPlugin({ title: 'Code Splitting' }), new webpack.NamedModulesPlugin(), new webpack.HotModuleReplacementPlugin() ], output: { filename: '[name].[hash:5]js', path: path.resolve(__dirname, 'dist'), hotUpdateChunkFilename: 'hot/hot-update.js', //js hotUpdateMainFilename: 'hot/hot-update.json', //json }