How integrating a third-party framework into iOS Unreal Engine project in Xcode works?

I’m new to unreal engine. I have been trying to understand how getting input from a 3th party app on an IOS mobile app works. It can either be an input from any app (like facebook) or any information from the phone (like current UTC time, weather in the current location etc.) How does this process works? Are there any resources online that can be downloaded? I know I have to create a third-party module in UE4. That’s the only step I managed to get so far. Can someone please explain me how does this process works? I feel like it must be a simple protocol, but I wasn’t able to find anything on the AnswerHub.

Thanks in advance:)