Swift 5+
First of all you have to define 2 variables globally inside your view controller.
var player: AVPlayer!
var playerViewController: AVPlayerViewController!
Here I'm adding player to a desired view.
@IBOutlet weak var playerView: UIView!
Then add following code to the viewDidLoad method.
let videoURL = URL(string: "videoUrl")
self.player = AVPlayer(url: videoURL!)
self.playerViewController = AVPlayerViewController()
playerViewController.player = self.player
playerViewController.view.frame = self.playerView.frame
playerViewController.player?.pause()
self.playerView.addSubview(playerViewController.view)
If you are not defining player and playerViewController globally, you won't be able to embed player.