load .env in webpack config

webpack.config.js

require('dotenv').config({ path: path.resolve( __dirname, '../../.env' ) }); 

module.exports = {

    ...
  
    plugins: [
        new HtmlWebpackPlugin( { template: './src/index.html' } ),

        new webpack.DefinePlugin( {
            "process.env": JSON.stringify(process.env)
        } ),

    ],

    ...
  
};
  
/** 

  Now in html file use <%= process.env.GTAG_ID %>

*/