How to create an invoice in invoices.zoho?

How to create an invoice in invoices.zoho?

    I have some code to create an invoice in invoices.zoho:
    2. $invoice = array(
    3.     'customer_id' => 918439000000063105,
    4.     'contact_persons' => array('918439000000063085'),
    5.     'invoice_number' => 'TEST-00001',
    6.     'reference_number' => '',
    7.     'template_id' => 918439000000017001,
    8.     'date' => '2017-09-28',
    9.     'payment_terms' => 0,
    10.     'payment_terms_label' => 'Pagadero a la recepcion',
    11.     'due_date' => '2015-10-28',
    12.     'discount' => 0,
    13.     'is_discount_before_tax' => true,
    14.     'discount_type' => '',
    15.     'is_inclusive_tax' => false,
    16.     'exchange_rate' => 0.103627,
    17.     'recurring_invoice_id' => '',
    18.     'invoiced_estimate_id' => '',
    19.     'salesperson_name' => '',
    20.     'custom_fields' => array(),
    21.     'line_items' => array(
    22.         array(
    23.             'item_id' => 918439000000063265,
    24.             'project_id'  => '',
    25.             'expense_id'  => '',
    26.             'salesorder_item_id'  => '',
    27.             'name'  => 'Khách sạn Hạ Long-Luxury',
    28.             'description' => '',
    29.             'product_type' => 'goods',
    30.             'item_order' => 1,
    31.             'rate'  => 120,
    32.             'unit'  => '',
    33.             'quantity'  => 2.0,
    34.             'discount'  => 0,
    35.             'tax_id'  => ''
    36.         )
    37.     ),
    38.     'payment_options' => array(),
    39.     'allow_partial_payments' => false,
    40.     'custom_body' => '',
    41.     'custom_subject' => '',
    42.     'notes' => 'T.C. $ 9,65',
    43.     'terms' => '',
    44.     'shipping_charge' => 0.0,
    45.     'adjustment' => 0.0,
    46.     'adjustment_description' => 'Ajuste'
    47. );

    49. $url = 'https://invoice.zoho.com/api/v3/invoices/';
    50. $data = array(
    51.   'authtoken'     => '{AUTHORTOCKEN}',
    52.   'JSONString'    => $invoice,
    53.   "organization_id"   => '{organization_id}',
    54.   "send"                  => false
    55. );
    56. $ch = curl_init($url);
    57. curl_setopt_array($ch, array(
    58.   CURLOPT_POST => 1,
    59.   CURLOPT_SSL_VERIFYPEER => false,
    60.   CURLOPT_SSL_VERIFYHOST => false,
    61.   CURLOPT_POSTFIELDS => http_build_query($data),
    62.   CURLOPT_RETURNTRANSFER => true,
    63.   CURLOPT_POST => true,
    64.   CURLOPT_HTTPHEADER => array("Content-Type:application/x-www-form-urlencoded")
    65. ));

    67. $response = curl_exec($ch);
    68. $response = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    69. curl_close($ch);

    71. var_dump($response);
    Why I alway get message error 400 or ' {"code":4,"message":"Invalid value passed for JSONString"} '?