Newbie needs help setting up webhooks in Zoho CRM

Newbie needs help setting up webhooks in Zoho CRM

I am complete newbie when it comes to API's. I want to use Zoho CRM webhooks to create invoices in Zoho Books. I have read through Zoho Books API info and used its sample request JSONstring just to test the functionality. I have yet to get any results with the CRM webhooks.  What am I doing wrong? Is this even possible? Here is a screen shot of what I have: 

Any help is much appreciated! JSONstring is below:


{
      "customer_id": "460000000026049",
      "contact_persons": [
        "460000000026051"
      ],
      "invoice_number": "100001",
      "reference_number": "12345",
      "template_id": "460000000000153",
      "date": "2013-08-05",
      "payment_terms": 15,
      "payment_terms_label": "Net 15",
      "due_date": "2013-08-20",
      "discount": "10.00%",
      "is_discount_before_tax": true,
      "discount_type": "entity_level",
      "exchange_rate": 1.00,
      "recurring_invoice_id": "",
      "invoiced_estimate_id": "",
      "salesperson_name": "John Michael",
      "custom_fields": [
        {
          "index": 1,
          "value": "15 Aug 2013"
        },
        {
          "index": 2,
          "value": "2 Days"
        },
        {
          "index": 3,
          "value": "0.99$/Day"
        }
      ],
      "line_items": [
        {
          "item_id": "460000000027009",
          "project_id": "",
          "expense_id": "",
          "name": "Hard Drive",
          "description": "500GB, USB 2.0 interface 1400 rpm, protective hard case.",
          "item_order": 1,
          "rate": 120.00,
          "unit": "Nos",
          "quantity": 4.00,
          "discount": 0.00,
          "tax_id": "460000000027005"
        },
        {
          "item_id": "460000000027017",
          "project_id": "",
          "expense_id": "",
          "name": "Premium Plan - Web hosting",
          "description": "10 GB Space, 300 GB Transfer 100 Email Accounts 10 MySQL Databases",
          "item_order": 2,
          "rate": 33.00,
          "unit": "Nos",
          "quantity": 1.00,
          "discount": 0.00,
          "tax_id": "460000000027007"
        }
      ],
      "payment_options": {
        "payment_gateways": [
          {
            "gateway_name": "paypal",
            "additional_field1": "standard"
          },
          {
            "gateway_name": "stripe",
            "additional_field1": ""
          }
        ]
      },
      "allow_partial_payments": true,
      "custom_body": "",
      "custom_subject": "",
      "notes": "Thanks for your business."
      "terms": "Terms and conditions apply."
      "shipping_charge": 7.50,
      "adjustment": 15.50,
      "adjustment_description": "Adjustment"
    }