Deluge map question

Deluge map question

I'm creating a custom function that will create a record in zoho creator using payment record information from zoho books.  I've been able to successfully create a record in ZC but I'm unable to get the invoice_id from the customer_payment map.

Below is the code:
paymentMap = Map();

//set order to payment invoice id - this is not working
paymentMap.put("Order",customer_payment.get("invoices[0].invoice_id"));

paymentMap.put("Description",customer_payment.get("card_type"));
paymentMap.put("Payment_ZB_ID",customer_payment.get("payment_id"));
response = zoho.creator.createRecord("XXXXX","XX","Payment",paymentMap);
info response;

Below is the map that is available:

customer_payment

{

 "payment_id": "11111111111111111",

 "payment_number": "1",

 "payment_number_prefix": "",

 "payment_number_suffix": "1",

 "documents": [],

 "customer_id": "11111111111111111",

 "customer_name": "John Doe",

 "payment_mode": "Stripe",

 "card_type": "visa",

 "card_type_formatted": "Visa",

 "date": "2019-03-04",

 "date_formatted": "03/04/2019",

 "account_id": "11111111111111111",

 "account_name": "Stripe Clearing",

 "account_type": "payment_clearing",

 "account_type_formatted": "Payment Clearing Account",

 "currency_id": "11111111111111111",

 "currency_code": "USD",

 "exchange_rate": 1,

 "exchange_rate_formatted": "$1.00",

 "amount": 1,

 "amount_formatted": "$1.00",

 "unused_amount": 0,

 "unused_amount_formatted": "$0.00",

 "bank_charges": 0.33,

 "bank_charges_formatted": "$0.33",

 "tax_account_id": "",

 "is_client_review_settings_enabled": false,

 "tax_account_name": "",

 "tax_amount_withheld": 0,

 "tax_amount_withheld_formatted": "$0.00",

 "discount_amount": 0,

 "discount_amount_formatted": "$0.00",

 "description": "Stripe processing fees : $0.33 ",

 "reference_number": "12345",

 "online_transaction_id": "12345",

 "settlement_status": "",

 "settlement_status_formatted": "",

 "invoices": [

  {

   "invoice_number": "11111111111111111",

   "invoice_payment_id": "11111111111111111",

   "invoice_id": "11111111111111111",

   "amount_applied": 1,

   "amount_applied_formatted": "$1.00",

   "tax_amount_withheld": 0,

   "tax_amount_withheld_formatted": "$0.00",

   "discount_amount": 0,

   "discount_amount_formatted": "$0.00",

   "total": 1,

   "total_formatted": "$1.00",

   "balance": 0,

   "balance_formatted": "$0.00",

   "date": "2019-03-04",

   "date_formatted": "03/04/2019",

   "due_date": "2019-03-04",

   "due_date_formatted": "03/04/2019",

   "price_precision": 2,

   "apply_date": "",

   "apply_date_formatted": ""

  }

 ],

 "payment_refunds": [],

 "last_four_digits": "1234",

 "template_id": "11111111111111111",

 "template_name": "Elite Template",

 "page_width": "8.27in",

 "page_height": "11.69in",

 "orientation": "portrait",

 "template_type": "elite",

 "template_type_formatted": "Elite",

 "attachment_name": "",

 "can_send_in_mail": true,

 "can_send_payment_sms": false,

 "is_payment_details_required": true,

 "custom_fields": [],

 "custom_field_hash": {},

 "imported_transactions": []

}