Are there ways to find out if an app is connecting to the internet?

Question

iOS

There is an application for iOS, iphone.
It is known that it should not connect to the Internet. That is, this is not a messenger or any other application that requires access to the Internet.
1) Are there ways to find out if an app is connecting to the internet?
2) Are there any special applications that allow you to track the traffic of applications installed on your smartphone?
3) Will wireshark help here?

Answer 1

if through a cellular connection, then in the settings -> cellular communication - see which applications have access to the Internet and how much traffic they used.

Answer 2

phone -> wifi -> [interface1 (router with wireshark) interface2] -> internet