AgoraVideoViewController.swift

@IBAction func didTapInvite(_ sender: Any) {
    let storyboard = UIStoryboard(name: "JoinFriendViewController", bundle: nil)
    let joinVC = storyboard.instantiateInitialViewController()!

    // Use the popover presentation style for your view controller.
    joinVC.modalPresentationStyle = .popover

    if let joinFriendVC = joinVC as? JoinFriendViewController {
        joinFriendVC.delegate = self
    }

    // Present the view controller.
    self.present(joinVC, animated: true) {

    }
}