mutation CreateCustomer($request: CreateCustomerCommandRequestInput!) {
  CreateCustomer(request: $request) {
    customerId
  }
}

{
  "request": {
    "customerGroupId": "id",
    "billingAddress": {
      "street": "string",
      "city": "string",
      "countryIso": "string"
    }
  }
}

{
  "data": {
    "CreateCustomer": {
      "customerId": "id"
    }
  }
}