Lander

function new_users($name, $last_name){
    global $user;
    $fullname = ['name' => $name, 'last_name' => $last_name];
    $user[] = $fullname;
    echo "\n";
    var_dump($user);
}

while ($myrow_index = mysqli_fetch_array($result_index)) {
    ...
}

button.my {
    width: 212px;
}

$sum = 1;
$mysqli->query("UPDATE orders SET redeemed = '$change',  amount = amount - '$sum' WHERE id = '$id'");