Test Cases for Integration Testing for Instant Messaging Chat App

I have created a Instant Messaging Chat App using Telegram Open Source Code for my College Project. Most of the functionality are similar to WhatsApp. I have created Test Cases for Unit Testing. But stuck in writing test cases for Integration Testing because exactly I don't know what to write in test case for integration testing. Here I have attached test cases Format/Template for Unit testing.

Please suggest test cases with Expected Input and Expected result for Integration testing-