If you have disabled notifications for the Authenticator app in your smartphone’s settings, the screen for entering the two-digit code will not appear.
(Example) iPhone (iOS): Go to the “Settings” app > “Notifications” > “Authenticator,” or select “Authenticator” from the list of apps at the bottom of the “Settings” app and turn on the “Allow Notifications” switch (green).
(Example) Android: Go to “Settings” > “Apps” or “App Manager” > “Authenticator” > “Notifications,” and turn on “Show notifications.”
*Menu names may vary by manufacturer, so please check the “Search for Settings” feature in the “Settings” app or look for the appropriate option based on your device’s settings.