Create "Invisible Ink" effect in Swift or SwiftUI

Question

I'm trying to create an "Invisible Ink" animated view, like the one existed in Messages app.
As I could see, Apple have a framework for it called CKInvisibleInkImageEffectView but it's private.

I was able to get a similar result using the private one, but I'd like to create it from scratch or using an open source framework.

Result using the private API:

class ViewController: UIViewController {

  @IBOutlet private weak var contentView: UIView!

  override func viewDidLoad() {
    super.viewDidLoad()
    updateUI()
  }

  private func updateUI() {
    if let invisibleInk = getInvisibleInkEffectView() {
      invisibleInk.frame = CGRect(origin: .zero, size: contentView.bounds.size)

      contentView.addSubview(invisibleInk)

      invisibleInk.layer.cornerRadius = invisibleInk.bounds.height / 2
      invisibleInk.backgroundColor = .systemBrown
      invisibleInk.layer.masksToBounds = true
    }
  }

  private func getInvisibleInkEffectView() -> UIView? {
    dlopen("/System/Library/PrivateFrameworks/ChatKit.framework/ChatKit", RTLD_NOW)
    let invisibleInkView = NSClassFromString("CKInvisibleInkImageEffectView") as? UIView.Type
    let view = invisibleInkView?.init()
    return view
  }
}

Effect in Message App I would like to implement:

Anyone knows if there is any open source framework or how to create it in Swift or SwiftUI?

Thanks