Apollo Server 4 / Koa – Cannot read properties of undefined (reading ‘headers’)

i upgraded to apollo 4 and i am using koa js. But there are some problems with context. Authentication process does not work. Authentication time I get an error like this:

**"message": "Cannot read properties of undefined (reading ‘headers’)"
"code": "INTERNAL_SERVER_ERROR",

@[email protected][email protected]/node_modules/@apollo/server/dist/esm/utils/schemaInstrumentation.js:36:28)

backend/graphql/resolvers/posts.js:31:20

backend/util/check-auth.js:5:36**

import { ApolloServer } from "@apollo/server";
import { ApolloServerPluginDrainHttpServer } from '@apollo/server/plugin/drainHttpServer';
import corsKoa from "@koa/cors";
import graphqlUploadKoa from 'graphql-upload/graphqlUploadKoa.mjs';
import { koaMiddleware as apolloServerKoa } from "@as-integrations/koa";
import http from "http";
import Koa from "koa";
import bodyParserKoa from "koa-bodyparser";

const app = new Koa();

import typeDefs from "./graphql/typeDefs.js"
import resolvers from "./graphql/resolvers/index.js"


const httpServer = http.createServer(app.callback());

const server = new ApolloServer({
    typeDefs,
    resolvers,
     context: ({ req }) => ({ req }),
    plugins: [ApolloServerPluginDrainHttpServer({ httpServer })],
});

await server.start();

app.use(corsKoa());
app.use(
  graphqlUploadKoa({
    maxFileSize: 10000000, // 10 MB
    maxFiles: 20,
  })
);
app.use(bodyParserKoa());
app.use(apolloServerKoa(server));

httpServer.listen(process.env.PORT, () => {
  console.info(
    `Serving https://localhost:${process.env.PORT} for ${process.env.NODE_ENV}.`
  );
});

Check-auth file:

import { GraphQLError } from "graphql"
import jwt from "jsonwebtoken"

export default (context) => {
    const authHeader = context.req.headers.authorization;
    if(authHeader) {
        const token = authHeader.split("Bearer ")[1];
        if(token) {
            try {
                const user = jwt.verify(token, process.env.SECRET_KEY);
                return user
            } catch(err) {
                throw new GraphQLError('Invalid/Expired token');
            }
        } 
        throw new Error("Authentication token must be 'Bearer [token]");
    } 
    throw new Error('Authorization header must be provided');
}

Solving the error I encountered in the backend I wrote with apollo server 4