Swift: Error when trying to access a class method through a shared instance

Question

class MoviesViewController5: UIViewController {
     static let sharedInstance: MoviesViewController5 = MoviesViewController5()
  
    func fillPage2(menuId menuId:String) {
        // ...
     }
}
  

When I try to access fillPage2 like this:

class TabsBarController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let tab4ViewController = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(identifier: "MoviesViewController5") as! MoviesViewController5
        // Add each ViewController to your viewControllers array
        
        // This throws an error
        tab4ViewController.sharedInstance.fillPage2(menuId: "2")
        // Static member 'sharedInstance' cannot be used on instance of type 'MoviesViewController5'
    }
    
}

This is the error:

Static member 'sharedInstance' cannot be used on instance of type 'MoviesViewController5'

tab4ViewController will actually represent the view. So I need to call the fillPage2 method on it.
Any idea what I'm doing wrong?