How to link viewDidLoad when I don't have UIViewController

I'm trying to link a Mapbox example class to my IOS app. The example class implemented viewDidLoad method, so I assume I should instantiate this code inside a UIViewController file right?

But unfortunately I don't have that file. I'm using react native and I assume I should have at least AppDelegate and UIViewController files correct? But I don't have it. I only have the UIViewController instantiated in AppDelegate.m like so:

UIViewController *rootViewController = [UIViewController new];

rootViewController.view = rootView;
self.window.rootViewController = rootViewController;

Is this the place where I should "link" the example class so that the viewDidLoad will be triggered?