Intro I wanted to use Nest.js and WebRTC(node-webrtc). NestJS - A progressive Node.js framework Documentation | NestJS - A progressive Node.js framework And because I wanted to try with simple page(not use JavaScript frameworks), I added static HTML, CSS, JavaScript into a Nest.js project. Prepare Install First, I installed @nestjs/cli. First steps | NestJS - A progressive Node.js framework As same as last time , I couldn't do global install because I had used Volta. But I could installed by volta. volta install @nestjs/cli Create project nest new nest-web-rtc-sample volta pin node@12 Run npm start After doing "npm start", I could getting "Hello World!" from http://localhost:3000. Add static files I could add static files by two ways. @nestjs/serve-static First one of them was using "serve-static". Serve Static | NestJS - A progressive Node.js framework npm install --save @nestjs/serve-static And I needed adding a module into app.modu