Situation
I use Twilio iOS SDK for my iOS Voip application.
Currently, I'm trying to call from any numbers to my Voip application developed by Twilio iOS SDK. The Voip application has already got call and accept it properly. However, the caller can't hear the voice from the phone which installed Voip application. I guess it's because the microphone for the Voip application is turned off, but I confirmed the voice section for the application does not appear on the settings of iOS when I reach to
[settings -> privacy -> microphone]
Question
How can I make my Voip application show on the microphone settings of iOS?