Unable to process your request. Please verify if the name and value is appropriate for the "xmlData" parameter.

Unable to process your request. Please verify if the name and value is appropriate for the "xmlData" parameter.

Hello Zoho team,
I am facing a issue with insert lead api.
I am posting the data through CURL and every time it returns this error message "Unable to process your request. Please verify if the name and value is appropriate for the "xmlData" parameter.".
Anybody please help me.

Here is my code - 

        $leadXml = '<Leads>
        <row no="1">
        <FL val="Company">printvenue</FL>
        <FL val="First Name">ashish</FL>
        <FL val="Last Name"><kumar</FL>
        <FL val="Phone">1234567898</FL>
        <FL val="Home Phone">0987654321</FL>
        <FL val="Other Phone">1212211212</FL>
        <FL val="Fax">02927272626</FL>
        <FL val="Mobile">292827622</FL>
        </row>
        </Leads>';

        $authtoken = "235xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
        $leadUrl = 'https://crm.zoho.com/crm/private/xml/Leads/insertRecords?';

        $ch = curl_init($leadUrl);
        curl_setopt($ch, CURLOPT_VERBOSE, 1);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));
        
        $query = "newFormat=1&authtoken=$authtoken&scope=crmapi&xmlData=$leadXml";
        
        curl_setopt($ch, CURLOPT_POSTFIELDS, $query);
        $response = curl_exec($ch);
        curl_close($ch);