How to change typeDefs and resolvers after startup when using apollo server?

Question

I have hello world code with apollo server:

const startApolloServer = async (typeDefs: any, resolvers: any): Promise<void> => {
    const app = express();
    const httpServer = http.createServer(app);

    const config = {
        typeDefs,
        resolvers,
        // csrfPrevention: true,
        plugins: [ApolloServerPluginDrainHttpServer({ httpServer })],
    };

    const server = new ApolloServer(config);  

    await server.start();
    server.applyMiddleware({ app });
    await new Promise<void>(resolve => httpServer.listen({ port: 4000 }, resolve));
    console.log(`🚀 Server ready at http://localhost:4000${server.graphqlPath}`);
};

I can set typeDefs and resolvers during the boot proces in my app.

But is there any way how to change schema/resolvers after startup? For example in every request? Or apply some request middleware to resolve schema/resolvers?