When you're passing arguments in code, it's generally better to avoid constructing the whole query/mutation string yourself. Instead, you can use $ syntax to define variables in your operation, and pass the variables as a separate map. See GraphQL variable documentation.

Note: Any query or mutation arguments of GraphQL type String must be provided to the server as variables instead of inline. An $id is of type ID permitting it to be defined inline.

Operation
query ($id: ID!) {
  business(id: $id) {
    name
    phone
  }
}
Operation Variables
{
  "id": "QnVzaW5lc3M6MWRhMmExNzctNzg2OC00NmMxLTgzMzktM2M4NjdlZDJlZGQ5"
}
Response
{
  "data": {
    "business": {
      "name": "Smith Consulting",
      "phone": null
    }
  }
}
Updated: