Problem with Kerberos authentication on a proxy server via Python requests

Question

I'm trying to implement sending messages to a Telegram bot using Python using the requests library.

Here's a code snippet:

import requests
from requests_kerberos import HTTPKerberosAuth

answer = requests.get(url, {'http':'http://prx.ies.local:3128'}, auth=HTTPKerberosAuth())

As a result, I get the following error: Caused by ProxyError('Unable to connect to proxy', OSError('Tunnel connection failed: 407 Proxy Authentication Required'))

Can you tell me how to authenticate on an HTTP proxy using requests, if the proxy uses the Kerberos protocol to authenticate users.

P.S. Before this I use kinit to get the ticket