You might not be receiving push notifications for a variety of reasons:
Push notifications are not enabled in the SportsEngine mobile app.
You haven't updated the SportsEngine mobile app to the latest version.
Your iOS/Android device's app notification settings have not been enabled for the SportsEngine mobile app.
Updating Your App to the Latest Version and Updating Your Device's App Settings:
The steps to do these two functions vary between devices and their operating systems. If you are unsure of how to perform these tasks, a simple search using the search engine of your choosing (Google, Bing, etc.) should be able to help.