I search in it's develop document, but didn't find the method.
https://develop.zendesk.com/hc/en-us/community/posts/360001687168-How-can-I-get-unread-message-count-related-to-tickets-in-android-and-iOS
The link is too old to get useful solution.
Find the method:
ZDKRequestProvider().getUpdatesForDevice { requestUpdates in }