I must admit, it’s quite tricky to set up a second entry point. In my case I needed to load the app with different headers through different index.html depending on the domain.

The only solution I found was to tell webpack directly, in my quasar.conf I have something like :

const env = require('quasar-dotenv').config();
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = function (ctx) {
   return {
      ...
      build: {
         ...
         extendWebpack(cfg) {
            ...
            cfg.plugins.push(
               new HtmlWebpackPlugin({
                  template: `${__dirname}\\src\\index2.template.html`,
                  filename: 'index2.html',
                  chunks: 'all',
                  ctx: ctx,
                  process: { env: env },
                  productName: "PageTitle",
                  productDescription: "PageDescription"
               })
            );
         }
      }
   }
}

/!\ The second index will be generated referencing the same assets and bundle.js