How to geckodriver anonymous firefox

[snippsat]

I guess you mean headless as it called.

from selenium.webdriver.firefox.options import Options

#-- Setup
options = Options()
options.add_argument("--headless")
browser = webdriver.Firefox(firefox_options=options, executable_path=r"path to geckodriver")
#-- Parse
browser.get('url')
title = browser.find_element_by_xpath('//title')
print(t.text)
#browser.quit()

So code over use selenium to parse,if use BeautifulSoup to parse you send code from selenium,you don't use urlopen(url),
but browser.page_source.
Otherwise there is no point to use Selenium(which should be used if need eg JavaScript,otherwise not).

# Give source code to BeautifulSoup
soup = BeautifulSoup(browser.page_source, 'lxml')
welcome = soup.select('head > title')
print(welcome.text)