To wake up a phone in the background or the killed state, you need to use push notifications.

Please refer to our documentation:
iOS SDK – Push Notifications | iOS SDK | QuickBlox
Android SDK – Push Notifications | Android SDK | QuickBlox
JavaScript SDK – Push Notifications | JavaScript SDK | QuickBlox
React Native SDK – Push Notifications | React Native SDK | QuickBlox
Flutter SDK – Push Notifications | Flutter SDK | QuickBlox

Also, please check our FAQ: How do I configure chat and video calling push notifications and offline messaging?

Additionally, these guides may be helpful:

Firebase push notifications configuration checklist

Does QuickBlox support VoIP notifications for iOS?

Please note that managing and configuring push notifications in the background mode or killed state is not a part of QuickBlox SDKs and the implementation is up to the client-side depending on the application workflow.

Feel free to check our official documentation for more information that will help you to integrate QuickBlox services into your applications / projects or contact our Support team by submitting a ticket if you have any other questions.