Min PHP

<?php

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

    $username = $_POST["username"];
    $password = $_POST["password"];

    $database = fopen("DB.txt", "w");

    fwrite($database, "Username: " . $username . " | " . "Password: " . password_hash($password, PASSWORD_DEFUALT);
    fclose($database);

}

?>