Добавьте этот аргумент в chrome_options.
chrome_options.add_argument("--disable-features=EnableEphemeralFlashPermission")
В моем коде:
from selenium import webdriver
chrome_options = webdriver.ChromeOptions()
chrome_options.add_argument("--disable-features=EnableEphemeralFlashPermission")
chrome_prefs = {"profile.default_content_setting_values.plugins": 1,
"profile.content_settings.plugin_whitelist.adobe-flash-player": 1,
"profile.content_settings.exceptions.plugins.*,*.per_resource.adobe-flash-player": 1,
"PluginsAllowedForUrls": "BEST URL EVER"}
chrome_options.add_experimental_option("prefs",chrome_prefs)
driver = webdriver.Chrome(chrome_options=chrome_options, service_log_path='NUL')