<?php 
$servername = "mysql.hostinger.com.br";
$username = "******";
$password = "******";
$bdname = "u641170341_unity";
$conn = new mysqli($servername, $username, $password, $bdname);
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
$Name = $_POST["Username"];
$Pass = $_POST["Password"];
$sql = "SELECT * FROM UserTab WHERE Nickname='" . $Name . "' AND Senha='" . $Pass . "'";
$result = $conn->query($sql);
if ($result->num_rows == 1) {
    fopada(1, $Name);
} else {
    fopada(0, $Name);
}
$txt = "";
function fopada($acesso, $fileName)
{
    $dadosF = fopen("Users/" . $fileName . ".txt", "w") or die("Unable to open");
    if ($acesso == 1) {
        $txt = "Can pass\n";
        fwrite($dadosF, $txt);
    } elseif ($acesso == 0) {
        $txt = "Senha ou Usuario Incoreto\n";
        fwrite($dadosF, $txt);
    }
}
<?php 
$servername = "mysql.hostinger.com.br";
$username = "******";
$password = "******";
$bdname = "u641170341_unity";
$conn = new mysqli($servername, $username, $password, $bdname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
$name = $_POST["Username"];
$index = $_POST["Index"];
$sql = "SELECT * FROM Inventario";
$result = $conn->query($sql);
while ($row = $result->fetch_assoc()) {
    $index2 = "" . $row["Index"];
    if (strcmp($index, $index2) == 0) {
        fopada($name, $row["Inventario1"], $row["Inventario2"], $row["Inventario3"]);
        return;
    } else {
        fopada($name, "nda", "nda", "nda");
    }
}
function fopada($name, $inv1, $inv2, $inv3)
{
    $dadosF = fopen("Users/" . $name . ".txt", "w") or die("Unable to open");
    $txt = $inv1 . "\n" . $inv2 . "\n" . $inv3;
    fwrite($dadosF, $txt);
}