data insertion functionality from third party app is not working on custom module

data insertion functionality from third party app is not working on custom module

hello all, I am inserting data from my PHP form to a custom module in CRM , but the data is not inserted. I tried the same procedure for lead and it is working fine for lead , but when I change it for custom module the code is executed and response as a successful but when I go to the custom module in my crm , there is no data Available.
This is my code....CustomModule6 is the name of the module in the CRM.

if(isset($_POST['submit'])) {
             $p_true_xml = "<CustomModule6>
<row no=\"1\">
        <FL val=\"test Name\">" . $last_name . "</FL>
        <FL val=\"test Owner\">" . $owner . "</FL>   
        <FL val=\"First Name\">" . $first_name . "</FL>  
    <FL val=\"Email\">" . $Email . "</FL>
    <FL val=\"Mobile\">" . $Mobile . "</FL>
    <FL val=\"Make\">" . $Make . "</FL>
    <FL val=\"Model\">" . $Model . "</FL>

</row>
    </CustomModule6>";   
        $p_true_url = " https://crm.zoho.com/crm/private/xml/CustomModule6/insertRecords?";
        $p_true_query = "authtoken=" . $auth . "&scope=crmapi&xmlData=" . $p_true_xml . "";

        $p_true1 = curl_init();
        curl_setopt($p_true1, CURLOPT_URL, $p_true_url);
        curl_setopt($p_true1, CURLOPT_FOLLOWLOCATION, 1);
        curl_setopt($p_true1, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($p_true1, CURLOPT_TIMEOUT, 60);
        curl_setopt($p_true1, CURLOPT_POST, 1);
        curl_setopt($p_true1, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($p_true1, CURLOPT_POSTFIELDS, $p_true_query);
        $p_true_response = curl_exec($p_true1);
        curl_close($p_true1);
        print_r($p_true_xml);
echo "data is inserted";
        }
        else {
            echo "else part is executed";
        }