not getting the mysql stored procedure returned integer value error using PHP PDO

Question

Created a mysql stored procedure and have accessed from php output parameter returns an integer value .cant get it at php code .any experts help to solve this would be appreciated . When i execute in he Mysql admin its returning 30 when i execute from php the session varibale return nothing ..

SQL CODE

CREATE PROCEDURE `Gettotdownlines`(
  IN `useridmobile` VARCHAR(20),
  OUT `totlevelcount` INT(6)
)
  BEGIN
    select count(*) INTO totlevelcount  from templeveltable;
  END

try {
    $sql = 'CALL Gettotdownlines(:useridmobile,@levelcount)';
    $stmt = $conn->prepare($sql);
    $stmt->bindParam(':useridmobile', $shopidd, PDO::PARAM_STR);
    $stmt->execute();
    $stmt->closeCursor();
    $row = $conn->query("SELECT @totlevelcount as ss")->fetch();
    if ($row) {
       
        if(count($row)>0)
        {
         $_SESSION['totaldownlines']=$row['ss'];
        }
        else
        {
             $_SESSION['totaldownlines'] =0;
        }
    }
} catch (PDOException $e) {
    die("Error occurred:" . $e->getMessage());
}

Answer 1

It is probably because you are fetching a wrong variable "SELECT @totlevelcount as ss" change it to "SELECT @levelcount as ss"