I need a way to save Item's texture as a png file. I was trying to understand, but it was not easy. You can simply save the contents of the entire window, not a separate Item. I tried to make a transparent window background and display a single item necessary to me. In this case when you save the image, background turns black.
I also tried:
layer.format: ShaderEffectSource.Alpha - nothing has changed
get the texture from QQuickItem::textureProvider()::texture() - textureProvider() always returns 0