def login_(browser):
    try:
        browser.get("some_url")
        # user credentials
        user = browser.find_element_by_xpath('//*[@id="username"]')
        user.send_keys(config('user'))
        password = browser.find_element_by_xpath('//*[@id="password"]')
        password.send_keys(config('pass'))
        login = browser.find_element_by_xpath('/html/body/div[1]/div/button')
        login.send_keys("n")
        time.sleep(1)
        sidebar = browser.find_element_by_xpath('//*[@id="sidebar"]/ul/li[1]/a')
        sidebar.send_keys("n")
        app_submit = browser.find_element_by_xpath('//*[@id="sidebar"]/ul/li[1]/ul/li[1]/a')
        app_submit.send_keys("n")
    except TimeoutException or NoSuchElementException:
        raise LoginException

Message: no such element: Unable to locate element: {"method":"xpath","selector":"//*[@id="sidebar"]/ul/li[1]/a"}
(Session info: headless chrome=67.0.3396.79)
(Driver info: chromedriver=2.40.565383 (76257d1ab79276b2d53ee97XXX),platform=Linux 4.4.0-116-generic x86_64)

def initiate_webdriver():
   option = webdriver.ChromeOptions()
   option.binary_location = config('GOOGLE_CHROME_BIN')
   option.add_argument('--disable-gpu')
   option.add_argument('window-size=1600,900')
   option.add_argument('--no-sandbox')
   if not config('DEBUG', cast=bool):
       display = Display(visible=0, size=(1600, 900))
       display.start()
       option.add_argument("--headless")
   else:
       option.add_argument("--incognito")
   return webdriver.Chrome(executable_path=config('CHROMEDRIVER_PATH'), chrome_options=option)