GraphQL subscriptions not working with 'graphql-ws' (NestJS)

Question

I'm trying to use 'graphql-ws'

GraphQLModule.forRoot<ApolloDriverConfig>({
  driver: ApolloDriver,
  autoSchemaFile: true,
  subscriptions: {
    'graphql-ws': true,
  },
}),

It's not working with 'subscriptions-transport-ws' too

GraphQLModule.forRoot<ApolloDriverConfig>({
  driver: ApolloDriver,
  autoSchemaFile: true,
  subscriptions: {
    'subscriptions-transport-ws': true,
  },
}),

Playground output

But working with 'installSubscriptionHandlers: true' instead subscriptions

GraphQLModule.forRoot<ApolloDriverConfig>({
  driver: ApolloDriver,
  autoSchemaFile: true,
  installSubscriptionHandlers: true,
}),

How can i fix it?