GitHub - OneSignal/OneSignal-Unity-SDK: OneSignal is a free push notification service for mobile apps. This plugin makes it easy to integrate your Unity app with OneSignal. https://onesignal.com
Android Mobile Notifications With Unity | Kodeco
Android Mobile Notifications With Unity | Kodeco
Troubleshooting Unity
Push Notification on Unity iOS
Mobile Notifications - Free Download | Unity Asset Collection
Implementing Android Notifications In Unity Game | by Zoran Šaško | The Startup | Medium