In order to to capture the HTTP/HTTPS message in iOS devices, please navigate to:
Certificate Menu -> Install Certificate on iOS Simulator
The following photo describes thee steps:
Install Root Proxyman Certificate on your machine: You can follow the macOS Guide.
Install Proxyman Certificate to available simulators, which you have opened at least one time.
3. Reset the simulators: Proxyman tries to reset all simulator, and it will load new Certificate.
After the installation, we can start capture and view HTTPS message by following SSL Proxying Doc
See detailed steps to debug an application on iOS Simulator with Proxyman