having difficulties calling functions in a different view controller - swift

Question

I'm having some difficulties calling a function in a view controller that is different than the one it was declared in. I've tried some methods from different posts on the site, but none of them are working for me.
class Housekeeping: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
var balance = 387563 //remove later, arbitrary value for testing
var username = "kaplan"
#objc func addTop() {
let balanceLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 150, height: 30))
balanceLabel.text = "\(balance)"
balanceLabel.textAlignment = .center
balanceLabel.font = UIFont.boldSystemFont(ofSize: 20)
balanceLabel.center = CGPoint(x: self.view.center.x*2-95, y: 50)
balanceLabel.textColor = UIColor(displayP3Red: 160/255, green: 160/255, blue: 160/255, alpha: 1.0)
view.addSubview(balanceLabel)
let genechipImg = UIImageView(image: UIImage(named: "genechip"))
genechipImg.frame = CGRect(x: 0, y: 0, width: 30, height: 30)
genechipImg.center = CGPoint(x: balanceLabel.center.x + 60, y: balanceLabel.center.y)
view.addSubview(genechipImg)
let usernameLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 130, height: 30))
usernameLabel.text = "Dr. \(username)"
usernameLabel.textAlignment = .center
usernameLabel.font = UIFont.boldSystemFont(ofSize: 20)
usernameLabel.center = CGPoint(x: 80, y: 50)
usernameLabel.textColor = UIColor(displayP3Red: 160/255, green: 160/255, blue: 160/255, alpha: 1.0)
view.addSubview(usernameLabel)
}
}
This addTop function was declared in a view controller named Housekeeping and I'm trying to call it on a second view controller named GeneLibrary but I can't figure out how. As you can see, the function doesn't do much just adds two labels at the top, which I'm trying to add on a subsequent view controller. Here's the second view controller I'm trying to pass it to:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
print("gene library scene running")
}
}
If anybody could please provide some insight I'd really appreciate it. Stay safe everybody, thanks!

Answer 1

Declare your function as static:
static func addTop() { print("hello") }
Then call it like so:
Housekeeping.addTop()

Answer 2

Without a context of your app, The solution is:
GeneLibrary().addTop()
This will get to the function and print hello, but I believe this is not your intention, as GeneLibrary() creates a new instance from GeneLibrary view controller, while there might already be another instance that you want to call in order to do what you want.
if you can provide more details I'll be glad to help.
UPDATE
as the second view controller is being presented:
let housekeepingVC = presentingViewController as? Housekeeping
housekeepingVC.addTop()
this will do the job