Please check the following settings to enable push notifications:
1. In your device's app settings for Tears of Themis, ensure all notifications and permissions are enabled.
2. In mobile data settings, enable Allow background data usage and Allow data usage while Data saver is on.
3. In battery settings, set the app's usage to Unrestricted or ensure your phone battery is above 85%.
4. In the game, navigate to System > Basic Settings and toggle Push Notifications to On.