Hello, I am trying to add item to Zoho inventory using nodejs POST request. But I keep getting the following error: 

1. {"code":4,"message":"Invalid value passed for JSONString"}
   

Here is the code for the POST request:

1. let form = {
   
2.         unit: "qty",
3.         item_type: "inventory",
4.         product_type: "goods",
5.         is_taxable: true,
6.         description: "description",
7.         attribute_name1: "Small",
8.         name: "Bags-small",
9.         rate: 6,
10.         purchase_rate: 6,
11.         reorder_level: 5,
12.         initial_stock: 50,
13.         initial_stock_rate: 500,
14.         sku: "SK123",
15.         upc: 111111111111,
16.         ean: 111111111112,
17.         isbn: 111111111113,
18.         part_number: 111111111114,
19.         attribute_option_name1: "Small",
20.         purchase_description: "Purchase description"
21.     };
22. 
    
23.     let formData = JSON.stringify(form);
24.     console.log(formData);
25. 
    
26.     request({
27.         headers: {
28.             'Authorization': 'Zoho-authtoken d9XXXXXXXXXXXXXXXXXd0f46',
29.             'organization_id': '667953382'
30.         },
31.         uri: 'https://inventory.zoho.com/api/v1/items?authtoken=d9XXXXXXXXXXXXXXXX0f46&organization_id=6XXXXXXX2',
32.         body: formData,
33.         method: 'POST'
34.     }, function (err, res, body) {
35.         console.log(body); // get error message here
    
36.     });
    

Although the JSON is valid, I get the same error when trying with Postman. Can you please let me know what I am missing here? Thank you