What should I do if I cannot receive Duo’s Push notification of 2FA service?

Please check the internet access if you cannot receive push notification. As some phones may have difficulty determining whether to use WiFi or cellular data, you can turn off one of the connection to resolve it.

You can choose to use “Passcode” if you have any problem in using “Push” notification.

Another is about Google Play Service in China, please visit “Does Duo Mobile work in China?” for the details.