Passing data from a table view to an Xcode view controller

I'm trying to pass data already saved in a Core Data from UITableView to a view controller . The code compiles to me without error but when I execute it does not present to me in UILabel the information that it would have to send.

This is the table view code:

import UIKit

class CostumerTableViewController: UITableViewController {
    var costumerArray:[Costumer] = []

    override func viewDidLoad() {
        super.viewDidLoad()
        self.tableView.reloadData()
        self.fetchData()
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return costumerArray.count
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
        let name = costumerArray[indexPath.row]
        cell.textLabel?.text = name.costumerName!
        return cell
    }

    override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
        let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
        if editingStyle == .delete {
            let costumerDelete = costumerArray[indexPath.row]
            context.delete(costumerDelete)
            (UIApplication.shared.delegate as! AppDelegate).saveContext()
            do {
                costumerArray = try context.fetch(Costumer.fetchRequest())
            } catch {
                print(error)
            }
        }
        tableView.reloadData()
    }

    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        let Storyboard = UIStoryboard(name: "Main", bundle: nil)
        let DvC = Storyboard.instantiateViewController(withIdentifier: "costumerDetailViewController") as! costumerDetailViewController
        let n = costumerArray[indexPath.row]
        let Cn = n.costumerName!
        DvC.getCostumerName = Cn
        self.navigationController?.pushViewController(DvC, animated: true)
    }

    func fetchData() {
        // se crea el context
        let  context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
        do {  // se hace el request del array
            costumerArray = try context.fetch(Costumer.fetchRequest())
        } catch {
            print(error)
        }
    }
}

And this one of the view controller :

import UIKit

class costumerDetailViewController: UIViewController {
    var getCostumerName = String()

    @IBOutlet weak var labelName: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
        labelName.text! = getCostumerName
    }
}

I see that I do not get an error anywhere, I do not see what is happening.