Denon AVR X2300W control via API

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

  local path = "http://192.168.1.13/goform/AppCommand.xml"
  
  local payload = [[
<?xml version="1.0" encoding="utf-8"?>
<tx>
  <cmd id="1">GetAllZonePowerStatus</cmd>
  <cmd id="1">GetAllZoneVolume</cmd>
  <cmd id="1">GetAllZoneSource</cmd>
  <cmd id="1">GetAllZoneMuteStatus</cmd>
</tx>
]]


         --"cmd0=PutMasterVolumeBtn%2F%3E&cmd1=aspMainZone_WebUpdateStatus%2F"
         --"cmd0=PutZone_InputFunction%2FTV&cmd1=aspMainZone_WebUpdateStatus%2F"

  local response_body = { }

  local res, code, response_headers, status = http.request
  {
    url = path,
    method = "POST",
    headers =
    {
      ["Accept"] = "*/*",
      ["Content-Type"] = "application/x-www-form-urlencoded",
      ["Content-Length"] = payload:len()
    },
    source = ltn12.source.string(payload),
    sink = ltn12.sink.table(response_body)
  }


itemtag = false
result = {}

-- callback for tag start
function starttag(parser, tag)
  -- create new storage in result table for each <item> tag
  if tag == 'zone1' then
    itemtag = true
    table.insert(result, {})
  end

  currtag = tag
end

-- callback for tag end
function endtag(p, tag)
  if tag == 'zone1' then
    itemtag = false
  end

  currtag = nil
end

-- callback for character data
function cdata(parser, text)
  -- check if parser is inside of <item> and either in <title> or <description>
  if itemtag and currtag then
    if currtag == 'zone1' then
      result[ #result ].Z1= text
      
    elseif currtag == 'dispvalue' then
      result[ #result ].Z1_Volume = text
      
    elseif currtag == 'source' then
      result[ #result ].Z1_source = text 
    end
    
  end
end

-- create parser
lxp = require('lxp')
parser = lxp.new({
  StartElement = starttag,
  EndElement = endtag,
  CharacterData = cdata,
})

if parser:parse(data) then
  -- Zone 1 State 
  if (result [1].Z1) == 'ON'then
  —-update group 
  end
  
  if (result [1].Z1) == 'OFF'then
    —update group 
  end

  -- Zone 1 Volume
  if(result [2].Z1_Volume) ~= last then
    —set new volume to group 
     last = result [2].Z1_Volume
  end
 
else
  log('parse failed')
end