how to make Float UIButton in programatically

Click this link: Float UIButton

Try this code in file swift or playground, this full code

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let button = UIButton(frame: CGRect(x: view.center.x, y: view.center.y, width: 100, height: 100))
        
        button.layer.cornerRadius = button.frame.size.height / 2
        button.layer.backgroundColor = UIColor.red.cgColor
        
        button.layer.shadowColor = UIColor.black.cgColor
        button.layer.shadowOffset = CGSize(width: 0.0, height: 0.5)
        button.layer.shadowOpacity = 1.0
        button.layer.shadowRadius = 4.0
        button.layer.masksToBounds = false
        
        view.addSubview(button)
    }
}