mkdir rxjs-init cd rxjs-init npm init -y npm install rxjs webpack webpack-dev-server typescript ts-loader npm install webpack-cli --save-dev modify file: package.json { "name" : "rxjs-init" , "version" : "1.0.0" , "description" : "" , "main" : "index.js" , "scripts": { "start": "webpack-dev-server --mode development" }, "keywords" : [], "author" : "" , "license" : "ISC" , "dependencies" : { "rxjs" : "^6.6.3" , "ts-loader" : "^8.0.12" , "typescript" : "^4.1.3" , ...