Adding Ad Banners in multiple UIViewcontroller app

I have built an app like 2 years ago using story board. The root view controller of the app is UINavigation controller and the root view controller loads view controllers as per user interaction. From root view controller, depending on user action 8 other view controllers can be presented in UINavigation.

Now I would to include banner ads to that app.The problem is since I originally implemented the app using story board and viewcontrollers, I am wondering where to add the code for ad banner.

I did some research and it looks like the likely option is to 1. Add a UIViewcontroller as a root view controller 2. Add a ContainerView to the UIViewcontroller 3. Make Exiting navigation controller as embedded segue from the container view 4. Add the ad banner (Want the ad banner at the bottom of the screen).

In Other words

Existing

--> UINavigationController -->(segue)-->LoginController-->(segue)-->MainpageController-->

Planned Modification

--> UIViewController-->(has)-->Containerview-->(embed segue)-->UINavigationController -->(segue)-->LoginController-->(segue)-->MainpageController-->

What I like to know is, is this the best approach to implement ad banners in my case? or can I have ad banner view is each and every view controller which may be presented in navigation controller?

Thanks