[Linphone-developers] Navigation -Push to custom view controller

[ios developer]

Hi Team , 
need help. I have some custom screens which I need to add in the linphone existing app. It does not allow me to push to the viewcontroller,
when I create a log for self.navigationController its return nil. 
So can you tell me how I can do this like native push and pop . I don't want to use the composite view option
Thanks