Transparent window with MacCatalyst and UIKit

Question

I want to make my view transparent.

I found really much code how it should work but nothing worked in my case. I haven't got a Scene Delegate, because I created the project as a Augmented Reality App.

The code I found was too old (I am working with swift5) or it didn't work, I don't know why.

Please make your answer as simple as possible.

Thanks and sorry for my bad English.