Register User For Unity

//After 778 string in /wp-login.php
$errors = register_new_user($user_login, $user_email);
//registerUserForUnity
        require_once "db-unity/db.php";
        $user = R::dispense('users');
        if ($user) {
            $user->username = $_POST['user_login'];
            $user->email = $_POST['user_email'];
            $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
            $charactersLength = strlen($characters);
            $randomString = '';
            for ($i = 0; $i < 10; $i++) {
                $randomString .= $characters[rand(0, $charactersLength - 1)];
            }
            $tmp = $randomString;
            while(R::findOne('wp_users', 'UID = ?', [$tmp]))
            {
                $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
                $charactersLength = strlen($characters);
                $randomString = '';
                for ($i = 0; $i < 10; $i++) {
                    $randomString .= $characters[rand(0, $charactersLength - 1)];
                }
                $tmp = $randomString;
            }
            $user->uid = $tmp;
            $user->gameDataJson0 = "Empty JSON";
            $user->gameDataJson1 = "Empty JSON";
            $user->gameDataJson2 = "Empty JSON";
            $user->gameDataJson3 = "Empty JSON";

            $user->name = "";
            $user->surname = "";
            $user->middlename = "";

            $user->specialty_1 = "Empty";
            $user->priority_1 = "0";
            $user->zno_competition_score_1 = "0";

            $user->specialty_2 = "Empty";
            $user->priority_2 = "0";
            $user->zno_competition_score_2 = "0";

            $user->specialty_3 = "Empty";
            $user->priority_3 = "0";
            $user->zno_competition_score_3 = "0";

            R::store($user);
        }