Не отправляются данные из формы в БД

<div class="reg-form">
            <form method="post" >
                <p><input id="name" name="nuame" type="text" placeholder="Name"></p>
                <p><input id="email" name="email" type="text" placeholder="Email"></p>
                <p><input id="password" name="pass" type="password" placeholder="Password">
                    <p><button id="submit-btn"  type="submit" name="submit-btn">Sing-UP</button></p>
                </form>
                <?php
session_start();
if(isset($_SESSION['user'])!="")
{
    header("Location: Main.php");
}
include_once 'dtb-conect.php';
 
if(isset($_POST['submit-btn']))
{
 
    // $uname = mysql_real_escape_string($_POST['nuame']);
    $uname = (isset($_POST['nuame']) ? $_POST['nuame'] : null);
    $email = mysql_real_escape_string($_POST['email']);
    $upass = md5(mysql_real_escape_string($_POST['pass']));
    $query= "INSERT INTO users (username,email,password) VALUES('$uname','$email','$upass')";
 
    mysqli_query($conn, $query);
 
    if(mysqli_query($conn, $query))
    {
        ?>
        <script>alert('successfully registered ');</script>
        <?php
    }
    else
    {
        ?>
        <script>alert('error while registering you...');</script>
        <?php
    }
}
?>
            </div>

$query= "INSERT INTO users (id,username,email,password) VALUES('','$uname','$email','$upass')";

$query= "INSERT INTO users (email,password,username,user_id) VALUES('$email','$upass','$uname','')";

qb()->table('users')->insert([
    'username' => $_POST['nuame'],
    'email' => $_POST['email'],
    'password' => md5($_POST['pass'])
])->run();

$email = mysqli_real_escape_string($conn,$_POST['email']);
$upass = md5(mysqli_real_escape_string($conn,$_POST['pass']));

mysqli_query($conn, $query);

 <?php
$servername = "localhost";
$username = "username";
$password = "";
$conn = mysqli_connect($servername, $username, $password);
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
else{
echo "Connected successfully";
}
?>

$query= "INSERT INTO users (email,password,username,user_id) VALUES('$email','$upass','$uname','')";

<?php
$servername = "localhost";
$username = "username";
$password = "";
$conn = mysqli_connect($servername, $username, $password);
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}
else{
echo "Connected successfully";
}
?>