__typename is undefined from sdk while using plug in "typescript-graphql-request"

**Describe the bug**

"__typename is undefined"

```
// codegen.js
...
plugins: [
'typescript',
'typescript-operations',
'typescript-graphql-request',
],
config: {
rawRequest: false,
withInterfaceTypename: false,
skipTypename: false,
},

// schema
type Me {
id: String
}

type Query {
me: Me
}

query getMe {
me {
id
}
}

// node.js
import { GraphQLClient } from 'graphql-request'

const client = new GraphQLClient('https://graphql')
const sdk = getSdk(client)

const data = await sdk.getMe()
console.log(data.__typename) // undefined, but should me "Me"