Max PHP - 2

<?php

if(isset($_POST["register"])) {

    $username = $_POST["username"];
    $password = $_POST["password"];
    $database = "Database.txt";

    $userdata = $username . " | " . password_hash($password, PASSWORD_DEFAULT) . PHP_EOL;

    file_put_contents($database, $userdata, FILE_APPEND);

    $databaseString = file_get_contents($database);
}

?>