Selenium + Chrome proxy authentication that actually works — a runtime MV3 extension https://quanticdata.io/blog/how-to-rotate-proxy-in-selenium-python/

qd_selenium_proxy.py

"""Authenticated proxies in Selenium + Chrome, without selenium-wire.

Chrome's --proxy-server flag accepts host:port only. Credentials in the URL are
ignored and you get a 407. The portable fix is a tiny MV3 extension generated at
runtime that answers the auth challenge — no extra dependency, works headless.

    pip install selenium
    export QD_PROXY_USER=... QD_PROXY_PASS=...
    python3 qd_selenium_proxy.py us

https://quanticdata.io/residential-proxies/
Guide: https://quanticdata.io/blog/how-to-rotate-proxy-in-selenium-python/
"""
import json
import os
import sys
import tempfile
import zipfile

from selenium import webdriver

HOST, PORT = "pr.quanticdata.io", 7777
USER = os.environ["QD_PROXY_USER"]
PASS = os.environ["QD_PROXY_PASS"]
COUNTRY = sys.argv[1] if len(sys.argv) > 1 else "us"
SESSION = sys.argv[2] if len(sys.argv) > 2 else None

username = "-".join([USER, "country", COUNTRY] + (["session", SESSION, "sessTime", "10"] if SESSION else []))

MANIFEST = {
    "manifest_version": 3,
    "name": "proxy-auth",
    "version": "1.0",
    "permissions": ["proxy", "webRequest", "webRequestAuthProvider"],
    "host_permissions": ["<all_urls>"],
    "background": {"service_worker": "background.js"},
}

BACKGROUND = f"""
chrome.proxy.settings.set({{
  value: {{
    mode: "fixed_servers",
    rules: {{ singleProxy: {{ scheme: "http", host: "{HOST}", port: {PORT} }},
             bypassList: ["localhost"] }}
  }},
  scope: "regular"
}});

chrome.webRequest.onAuthRequired.addListener(
  () => ({{ authCredentials: {{ username: {json.dumps(username)},
                                password: {json.dumps(PASS)} }} }}),
  {{ urls: ["<all_urls>"] }},
  ["blocking"]
);
"""

path = tempfile.mktemp(suffix=".zip")
with zipfile.ZipFile(path, "w") as z:
    z.writestr("manifest.json", json.dumps(MANIFEST))
    z.writestr("background.js", BACKGROUND)

options = webdriver.ChromeOptions()
options.add_extension(path)
# Headless "new" supports MV3 extensions; the old headless mode does not.
options.add_argument("--headless=new")

driver = webdriver.Chrome(options=options)
try:
    driver.get("https://ipinfo.io/json")
    print(f"country={COUNTRY}{f' session={SESSION}' if SESSION else ' (rotating)'}")
    print(driver.find_element("tag name", "body").text)
finally:
    driver.quit()
    os.unlink(path)