Webpack won't allow a non-string entry configuration value

I am trying to set up a Webpack (version 5) configuration that specifies multiple entry points using the "Object Syntax" as described in the Webpack documentation at https://webpack.js.org/concepts/entry-points/#object-syntax.

According to the Webpack documentation, I should be able to specify an "entry" configuration as (for example):

    module.exports = {
      entry: {
        app: './src/app.js',
        adminApp: './src/adminApp.js',
      },
    };

But when I try to run Webpack with this configuration, I get an error:

    [webpack-cli] Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
     - configuration.entry[0] should be a non-empty string.
       -> A module that is loaded upon startup. Only the last one is exported.

My full webpack.config.js is as follows:

    const HtmlWebpackPlugin = require('html-webpack-plugin');
    const path = require('path');
    
    module.exports = {
      entry: {
        'chunkone': './index1.js',
        'chunktwo': './index2.js'
      },
      mode: 'development',
      output: {
        path: path.resolve(__dirname, './dist'),
        filename: 'index_bundle.js',
      },
      target: 'web',
      devServer: {
        port: '5000',
        static: {
          directory: path.join(__dirname, 'public')
        },
        open: true,
        hot: true,
        liveReload: true,
        proxy: {
          '/api': 'http://localhost:8000',
        }
      },
      resolve: {
        extensions: ['.js', '.jsx', '.json'],
      },
      plugins: [
        new HtmlWebpackPlugin({
          template: path.join(__dirname, 'public', 'index1.html'),
          chunks: ['chunkone']
        }),
        new HtmlWebpackPlugin({
          template: path.join(__dirname, 'public', 'index2.html'),
          chunks: ['chunktwo']
        })
      ]
    };

and my package.json is as follows:

    {
      "name": "sandbox8a",
      "version": "1.0.0",
      "description": "",
      "main": "index.js",
      "scripts": {
        "test": "echo \"Error: no test specified\" && exit 1",
        "start": "start node .\\server\\server.js && webpack-dev-server .",
        "build": "webpack .",
        "ver": "webpack --version"
      },
      "keywords": [],
      "author": "",
      "license": "ISC",
      "devDependencies": {
        "html-webpack-plugin": "^5.5.3",
        "webpack": "^5.90.1",
        "webpack-cli": "^5.1.4",
        "webpack-dev-server": "^4.15.1"
      },
      "dependencies": {
      }
    }

Can anyone suggest what I may be missing here?

As answered by the Webpack developer at https://github.com/webpack/webpack/discussions/18057#discussioncomment-8407045, my webpack.config and package.json had several issues.

The corrected webpack.config is as follows:

const HtmlWebpackPlugin = require('html-webpack-plugin');
const path = require('path');
const webpack = require("webpack");

module.exports = {
  mode: 'development',
  entry: {
    'chunkone': './index1.js',
    'chunktwo': './index2.js'
  },
  output: {
    path: path.resolve(__dirname, './dist'),
    filename: '[name].bundle.js',
  },
  target: 'web',
  devServer: {
    port: '5000',
    static: {
      directory: path.join(__dirname, 'public')
    },
    open: true,
    hot: true,
    liveReload: true,
    proxy: {
      '/api': 'http://localhost:8000',
    }
  },
  resolve: {
    extensions: ['.js', '.jsx', '.json'],
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: path.join(__dirname, 'public', 'index1.html'),
      filename: "index1.html",
      chunks: ['chunkone']
    }),
    new HtmlWebpackPlugin({
      template: path.join(__dirname, 'public', 'index2.html'),
      filename: "index2.html",
      chunks: ['chunktwo']
    })
  ]
};

and the corrected package.json is as follows:

{
  "name": "sandbox8a",
  "version": "1.0.0",
  "description": "",
  "main": "index1.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "start node .\\server\\server.js && webpack-dev-server .",
    "build": "webpack",
    "ver": "webpack --version"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "html-webpack-plugin": "^5.6.0",
    "webpack": "^5.90.1",
    "webpack-cli": "^5.1.4",
    "webpack-dev-server": "^4.15.1"
  },
  "dependencies": {
  }
}