Update grade route.ts to Next 13

app/api/grade/route.ts

@@ -1,25 +1,23 @@
-import type { NextApiRequest, NextApiResponse } from 'next'
+import {NextResponse} from "next/server";
 
 import prisma from '@lib/prisma';
-
 interface IBody {
     key: string
     grade: number
 }
 
-export default async function handler(req: NextApiRequest, res: NextApiResponse) {
-    const body = req.body as IBody
-    if (req.method === 'POST') {
-        // Process a POST request
-        await prisma.grade.findFirst({where: {key: body.key}}).then(async (grade) => {
-            if (grade) {
-                await prisma.grade.create({data: {test: 1, grade: body.grade, key: body.key}})
-                res.status(200).json({message: 'Grade updated', cookie: 'voted=true'})
-            } else {
-                res.status(404).json({message: 'Key not found'})
-            }
-        })
-    } else {
-        // Handle any other HTTP method
-    }
+export async function POST(req: Request){
+    const body = await req.json() as IBody
+    await prisma.grade.findFirst({where: {key: body.key}}).then(async (grade) => {
+        if (grade) {
+            await prisma.grade.create({data: {test: 1, grade: body.grade, key: body.key}})
+            return new NextResponse(
+                JSON.stringify({message: 'Grade updated', cookie: 'voted=true'}), {status: 200}
+            )
+        } else {
+            return new NextResponse(
+                JSON.stringify({message: 'Key not found'}), {status: 404}
+            )
+        }
+    })
 }