Post Request with XML request body

[Hadeel]

I am trying to send the following command to SONY Bravia TV with REST API request.
While I successfully sent the exact same command with XML request body with Postman,
when I try with LM I am getting 500 Internal Server Error.
Am I missing something in my code?

Code:

local http = require("socket.http")
local ltn12 = require("ltn12")

path =  'http://172.16.1.11/sony/ircc'
payload = [[<?xml version="1.0"?>
<s:Envelope
    xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"
    s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
    <s:Body>
        <u:X_SendIRCC
            xmlns:u="urn:schemas-sony-com:service:IRCC:1">
            <IRCCCode>AAAAAgAAAJcAAAArAw==</IRCCCode>
        </u:X_SendIRCC>
    </s:Body>
</s:Envelope>]]

local response_body = { }
local res, code, response_headers, status = http.request
{
    url = path,
    method = "POST",
    headers =
    {
      ["Accept"] = "*/*",
      ["Host"] = "172.16.1.1",
      ["Content-Type"] = "application/xml",
      ["SOAPACTION"] = "urn:schemas-sony-com:service:IRCC:1#X_SendIRCC",
      ["X-Auth-PSK"] = "1707",
      ["Connection"] = "Keep-Alive",
      ["Content-Length"] = payload:len()
    },
   
    source = ltn12.source.string(payload),       
    sink = ltn12.sink.table(response_body)
}
log("Response:", table.concat(response_body))
log("Status:", status)
log("Code:", code)
log("Response Headers:", response_headers)
log("Result:", res)

The example code from SONY Bravia official is the follwoing.
https://pro-bravia.sony.net/ja/develop/i...entication

Thank you for your help in advance!