How do I get the back bar button item to show up in my navigation item in iOS?

Question

I am not able to show a back bar button item in my navigation item in my root view controller of my navigation controller.

I have tried setting different properties.

Other questions like this do not give me an answer that works.

Her is my code in my root view controller:

override func viewDidLoad() {
    super.viewDidLoad()

    print("viewDidLoad")

    navigationItem.leftItemsSupplementBackButton = true
    navigationItem.backBarButtonItem = UIBarButtonItem(title: "Button", style: .plain, target: nil, action: nil)
    navigationItem.setHidesBackButton(false, animated: true)
    navigationItem.leftItemsSupplementBackButton = true

}

Answer 1

Assigning to leftBarButtonItem instead of backBarButtonItem works for me:

override func viewDidLoad() {
    super.viewDidLoad()

    print("viewDidLoad")

    navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Button", style: .plain, target: nil, action: nil)
}