Swift Popup return value to parent viewcontroller

Question

i have a popup where i search for some values. if the user selected something in the popup, the value should returned to the parent Viewcontroller but i have no idea how to do it. To show the popup i created this:

 let popUpPreload = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "selectsellertyp") as! SelectSellerTypViewController


    self.addChild(popUpPreload)
    popUpPreload.view.frame = self.view.frame
    self.view.addSubview(popUpPreload.view)

    popUpPreload.didMove(toParent: self)

In my SelectSellerTypViewController i just wanna return the value through a button click so there is no special code:

SelectSellerTypViewController: UIViewController {
@IBAction func cancelaction(_ sender: Any) {
    removeAnimation()
}

@IBAction func startSearching(_ sender: Any) {
    // HEre i want to return the value
}
@IBAction func cancel(_ sender: Any) {
    removeAnimation()
}
@IBOutlet weak var rv: UITableView!
override func viewDidLoad() {
    super.viewDidLoad()
    showAnimate()
    // Do any additional setup after loading the view.
}



func showAnimate(){
    self.view.transform = CGAffineTransform(scaleX: 1.3, y: 1.3)
    self.view.alpha = 0.0
    UIView.animate(withDuration: 0.25, animations: {
        self.view.alpha = 1.0
        self.view.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
    });
}

func removeAnimation(){
    UIView.animate(withDuration: 0.25, animations: {
        self.view.transform = CGAffineTransform(scaleX: 1.3, y: 1.3)
        self.view.alpha = 0.0

    },completion:{(finished: Bool)in
        if finished{
            self.view.removeFromSuperview()
        }
    })
}

}