web-ext plugin for Webpack 5 Install yarn add -D webext-webpack-plugin npm add --save-dev webext-webpack-plugin Usage Javascript const WebExtWebpackPlugin = require('webext-webpack-plugin'); const path = require('path'); const baseDir = path.resolve(__dirname); const config = { plugins: [ new WebExtWebpackPlugin({ run: { firefox: 'C:\\Program Files\\Firefox Developer Edition\\firefox.exe', startUrl: ['https://google.com/'], }, }), ] }; TypeScript import * as path from 'path'; import * as webpack from 'webpack'; import WebExtWebpackPlugin from 'webext-webpack-plugin'; const baseDir = path.resolve(__dirname); const config: webpack.Configuration = { plugins: [ new WebExtWebpackPlugin({ run: { firefox: 'C:\\Program Files\\Firefox Developer Edition\\firefox.exe', startUrl: ['https://google.com/'], }, }), ] }; export default config; License MIT