getting Error while im start npm start on terminal

Error: Could not find a production build in the 'C:\Users\sai\06-onwards-to-a-bigger-project-starting-project.next' directory. Try building your app with 'next build' before starting the production server. https://err.sh/vercel/next.js/production-start-no-build-id at Server.readBuildId (C:\Users\sai\06-onwards-to-a-bigger-project-starting-project\node_modules\next\dist\next-server\server\next-server.js:146:355) at new Server (C:\Users\sai\06-onwards-to-a-bigger-project-starting-project\node_modules\next\dist\next-server\server\next-server.js:3:120) at createServer (C:\Users\sai\06-onwards-to-a-bigger-project-starting-project\node_modules\next\dist\server\next.js:2:638)
at start (C:\Users\sai\06-onwards-to-a-bigger-project-starting-project\node_modules\next\dist\server\lib\start-server.js:1:323) at nextStart (C:\Users\sai\06-onwards-to-a-bigger-project-starting-project\node_modules\next\dist\cli\next-start.js:19:233)
at C:\Users\sai\06-onwards-to-a-bigger-project-starting-project\node_modules\next\dist\bin\next:27:115 PS C:\Users\sai\06-onwards-to-a-bigger-project-starting-project>