ESP-8266, urequests installed manually.

Code:

import urequests as u
req = u.get("https://api.telegram.org/bot<my_token>/ ... my_chat_id>")
, i get this:

Traceback (most recent call last):
File "", line 1, in
File "/lib/urequests.py", line 112, in get
File "/lib/urequests.py", line 60, in request
OSError: -40

But for example, this works:
req = u.get("https://telegram-webhook-sample.herokuapp.com/")