public function ChangePassword($username, $password, $new_password) {
    $canUserLogin = $this->isLoginExist($username, $password);
    if($canUserLogin){
        $query = "UPDATE users SET password = $new_password WHERE username = $username";
        $inserted = mysqli_query($this->db->getDb(), $query);
        if($inserted == 1){
            $json['success'] = 1;
        }else{
            $json['success'] = 0;
        }
        mysqli_close($this->db->getDb());
    }else{
        $json['success'] = 2;
    }
    return $json;
}