im using Next.js 14.2.4

this is mine app/api/auth/[…nextauth]/route.ts

in npm run dev all works fine, but when I go npm run build I get this error:

app/api/auth/[…nextauth]/route.ts
Type error: Route “app/api/auth/[…nextauth]/route.ts” does not match the required types of a Next.js Route.
“handler” is not a valid Route export field.

import NextAuth, { AuthOptions } from 'next-auth';
import GoogleProvider from 'next-auth/providers/google';
import clientPromise from '../../../../lib/db';
import { MongoDBAdapter } from '@next-auth/mongodb-adapter';

export const authOptions: AuthOptions = {
  adapter: MongoDBAdapter(clientPromise),
  providers: [
    GoogleProvider({
      clientId: process.env.GOOGLE_ID ?? '',
      clientSecret: process.env.GOOGLE_SECRET ?? '',
      authorization: {
        params: {
          prompt: 'consent',
          access_type: 'offline',
          response_type: 'code',
        },
      },
      profile(profile) {
        return {
          id: profile.sub,
          name: profile.name,
          email: profile.email,
          image: profile.picture,
        };
      },
    }),
    // ...add more providers here
  ],
};

const handler = NextAuth(authOptions);

export default handler;
export { handler as GET, handler as POST };

Im expecting to solve the npm run build, I tried to change the export defaults