If you are using app router, the file should be route.js, and you don't need pages folder

https://nextjs.org/docs/app/building-your-application/routing/route-handlers

And I think api folder has to be inside app folder too

can you tell me the endpoint for calling ?

http://localhost:3000/api/route like this ?

not working on postman

can I not use pages folder alongside app folder ?

Yes you can, but it's not really useful.

Using that pages router API route the path would be /api/hello in your browser.

bro move the api folder inside of the app folder