graphql issue with route in golang

Question

I used router in my code as:

router := chi.NewRouter()

router.Use(auth.Middleware())
srv := handler.NewDefaultServer(generated.NewExecutableSchema(generated.Config{Resolvers: &graph.Resolver{}}))

router.Handle("/", playground.Handler("GraphQL playground", "/query"))
router.Handle("/query", srv)

and got error like :

{
  "errors": {
    "message": "Unexpected token p in JSON at position 4",
    "stack": "SyntaxError: Unexpected token p in JSON at position 4"
  }
}

but when I Try using it with http.Handle it doesn't show error but the code inside auth.middleware doesn't run at all.