How Focus modes work in iOS:
When you select a Focus mode, like Do not Disturb, Sleep, Work or Personal, you'll be only notified from the apps and contacts you selected, all other notifications will be silenced and won't appear on lockscreen, but will be still available in the notification center. Since the Telegram contacts are not recognized as iOS contacts, currently you can only choose to recieve all Telegram notifications/calls to lockscreen, or to silence all of them for a specific Focus mode, which is not ideal.
Right now the Focus Filters API is in beta. I think it could be applied for Telegram in following ways:
Additional possible features:
Info for developers:
People use Focus on macOS, iOS, and iPadOS to minimize distractions. For example, someone might use a Work Focus to hide notifications from personal email or message accounts. When someone engages a Focus, the system executes your app’s custom SetFocusFilterIntent. Define a version of this intent to update your app’s configuration and filter incoming notifications.