Here’s a working example that uses authentication directly in the proxy URL:

import requests
import json

username = "account"
password = "password"

proxies = {
    "http": f"http://{username}:{password}@gw.kindproxy.com:12000",
    "https": f"http://{username}:{password}@gw.kindproxy.com:12000",
}

def fetch(url):
    r = requests.get(url, proxies=proxies, timeout=30)
    try:
        data = r.json()
        print(json.dumps(data, indent=4))
    except Exception:
        print(r.text)

fetch("http://ipinfo.io")

This format works for both HTTP and SOCKS5 proxies (just change the protocol if needed).
It’s simple and doesn’t require extra authentication objects.

For more practical examples — including Python, Node.js, and curl — see:
kindproxy dot com / faq / code-examples