How to access index(GSI) with amplify API?

Hi,
Is the a way I can query data with index, both Partition and Sort keys, using the GraphQL API in android? I have already pulled down the index into my local project and its inside my query schema. Also I am able to query and generate results in my AppSyncConsole. But am unable to use this inside my android project? Using the example below is the any way I can use the index in the android project query?

``` type Customer @model @auth(rules: [{ allow: public }]) {
id: ID!
name: String! @index(name: "byNameAndPhoneNumber", sortKeyFields: ["phoneNumber"], queryField: "customerByNameAndPhone")
phoneNumber: String
accountRepresentativeID: ID! @index
```

Any links or suggestion is welcome. Thanks