Zoho Sheet API problem with parameter json_data

When I run the following Post request through Zoho Sheet API, I kept getting error. Could someone please help?

The purpose of the request is to update a row on Zoho Sheet with jsondata. The documentation of the request is in this link: https://www.zoho.com/sheet/help/api/v2/#CONTENT-Update-rows-with-JSON-data

https://sheet.zoho.com/api/v2/p5gob655bd7aexxxxa446c9a7bfe03109aade3?method=worksheet.jsondata.set&worksheet_name=Sheet2&json_data=[{"Name":"Joe","Region":"South","Units":284, "row_index":4},{"Name":"Beth","Region":"East","Units":290, "row_index":4}]

Error response is:

<!doctype html>
<html lang="en">

<head>
    <title>HTTP Status 400 – Bad Request</title>
    <style type="text/css">
        body {
            font-family: Tahoma, Arial, sans-serif;
        }

        h1,
        h2,
        h3,
        b {
            color: white;
            background-color: #525D76;
        }

        h1 {
            font-size: 22px;
        }

        h2 {
            font-size: 16px;
        }

        h3 {
            font-size: 14px;
        }

        p {
            font-size: 12px;
        }

        a {
            color: black;
        }

        .line {
            height: 1px;
            background-color: #525D76;
            border: none;
        }
    </style>
</head>

<body>
    <h1>HTTP Status 400 – Bad Request</h1>
</body>

</html>