Setup Apollo server v4 with apollo gateway and graphql-modules

I have try to setup apollo server with apollo gateway and graphql-module.
This is my repo of this setup: Graphql Demo
The server is running success but problem come when call api.
My resolver

Query: {
    me() {
      return { id: '1', username: '@ava' };

My API call response:

The return value for API me is null. But it should return { id: ‘1’, username: ‘@ava’ }.
Could you pls take a look on this and give me an advice? Thank you so much.

You’re creating two separate subgraph schemas. It looks like it was correct before. If you uncomment subgraphSchema and remove the call to buildSubgraphSchema here it works.

Thank you for reply.

I would like to add Graphql Module to this setup. So i use buildSubgraphSchema to build schema from typedefs and resolver from config of graphql module.