Subscribing to notification

To subscribe to notifications, the client must invoke the account.registerDevice query, passing in token_type and token as parameters that identify the current device. It is useful to repeat this query at least once every 24 hours or when restarting the application. Use account.unregisterDevice to unsubscribe.

The following token_types are supported:

1. FCM_V2_IOS_TEDR (Apple Push Notification Service)
2. FCM_V2_ANDROID (Google Firebase Cloud Messaging)
9. APNS_VOIP (Apple Push VoIP)
13. HMS (Huawei Mobile Services)
14. FCM_V2_IOS (Firebase SDK)
15. SSE (SSE Notifications)
16. FCM_V2_ANDROID_TEDR (FCM v2 Android TEDR)
17. IOS_TEDR_VOIP (FCM v2 iOS TEDR)

Принцип работы пуш-уведомлений описан здесь: https://core.telegram.org/api/push-updates