============ Test Servers ============ To run Telethon on a test server, use the following code: .. code-block:: python client = TelegramClient(None, api_id, api_hash) client.session.set_dc(dc_id, '149.154.167.40', 80) You can check your ``'test ip'`` on https://my.telegram.org. You should set `None` session so to ensure you're generating a new authorization key for it (it would fail if you used a session where you had previously connected to another data center). Note that port 443 might not work, so you can try with 80 instead. Once you're connected, you'll likely be asked to either sign in or sign up. Remember `anyone can access the phone you choose `__, so don't store sensitive data here. Valid phone numbers are ``99966XYYYY``, where ``X`` is the ``dc_id`` and ``YYYY`` is any number you want, for example, ``1234`` in ``dc_id = 2`` would be ``9996621234``. The code sent by Telegram will be ``dc_id`` repeated five times, in this case, ``22222`` so we can hardcode that: .. code-block:: python client = TelegramClient(None, api_id, api_hash) client.session.set_dc(2, '149.154.167.40', 80) client.start( phone='9996621234', code_callback=lambda: '22222' )