The listsubscribe method in the List Management API for Zoho campaigns doesn't work anymore.

The listsubscribe method in the List Management API for Zoho campaigns doesn't work anymore.

Hi,

It seems that there is a problem with the Zoho Campaigns API currently. When trying to subscribe a new user in a list using the listsubscribe method, I receive a response code of 200 but the response is empty.

Everything was working perfectly before. Was there any changes to the API?

Thanks

$postField = [
'authtoken' => ZOHO_AUTH_TOKEN,
'scope' => 'CampaignsAPI',
'version' => 1,
'resfmt' => 'JSON',
'listkey' => $_REQUEST['listKey'],
'contactinfo' => $zohoFormatedDataAsString
];

$curl_pointer = curl_init();

$url = 'https://campaigns.zoho.com/api/json/listsubscribe';
curl_setopt($curl_pointer, CURLOPT_URL, $url);
curl_setopt($curl_pointer, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl_pointer, CURLOPT_POSTFIELDS, $postField);

$result = curl_exec($curl_pointer); // The result is empty here !!!
$responseInfo = curl_getinfo($curl_pointer);
curl_close($curl_pointer);