The first step would be to ensure that notifications settings for Tango are enabled on your Apple device.
To enable notifications:
Tap on the Settings app
Tap on Notifications
Tap on Tango
Enable Allow Notifications
Make sure 'Alert Style When Unlocked' is set to Banners or Alerts
You can also set your preferences for Show in Notification Center, Sounds, Badge App Icon, and Show on Lock Screen.
The next step would be to enable notifications in Tango app:
Open Tango app
Tap on your Profile photo to access a Profile menu
Tap on Settings
Find Notifications and Sounds
Enable the options that are preferred to you
If after these steps you still don't receive notifications, please contact our Support team for further assistance.