how do you add left and right bar buttons to UIViewController in swift

Question

Why are my top navbar buttons not showing up in Swift? the following is hoe i have added them and am not sure why they are not showing up when running the code

class TermsAndConditionsVC: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .blue
        setBarButtons()
    }

    func setBarButtons() {
        navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(handleLogout))
        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Logout", style: .plain, target: self, action: #selector(handleLogout))
    }

}

Answer 1

    var addPostBarItem: UIBarButtonItem
    
    if #available(iOS 13.0, *) {
        addPostBarItem = UIBarButtonItem(image: .add, style: .plain, target: self, action: #selector(addPost))
    } else {
        addPostBarItem = UIBarButtonItem(title: "Add", style: .plain, target: self, action: #selector(addPost))
        // Fallback on earlier versions
    }
    navigationItem.rightBarButtonItems = [addPostBarItem]