$username = '****';
$password = '****';

$url = ' http://103.75.198.17/services/api/iperson.svc ';
$soapClient = new SoapClient($url);

$params = array(
   'username' => $username,
   'password' => $password,
   'person' => array(
      'CrmObjectTypeCode' => 'code1',
      'CrmObjectTypeIndex' => 24,
      'Categories' => array(
         array(
            'Key' => 'keyno'
         )
      ),
      'IdentityType' => 'Person',
      'FirstName' => $first_name,
      'LastName' => $last_name
   )
);

$result = $soapClient->SavePerson($params);

if ($result->SavePersonResult->Success) {
   echo json_encode($result, JSON_UNESCAPED_UNICODE);
} else {
   echo $result->SavePersonResult->Message;
}