How do i define an api route in next js 14?

I'm trying to build a simple REST api. I have a route.ts file inside of src/app/api/timetable folder. Here is my route.ts:

import { NextApiRequest, NextApiResponse } from "next";type ResponseData = {  message: string}export function GET(  req: NextApiRequest,  res: NextApiResponse<ResponseData>) {  res.status(200).json({ message: 'Hello from Next.js!' })}

So its just basic example from docs. When I call this endpoint at localhost:3000/api/timetable I'm getting TypeError: res.status is not a function.

I'm using app router, typescript has the version 5.1.3, next js is 14.0.3

I tried to place it inside pages folder (like page router), it didn't help.