Qt Quick 3D use transparent textures with Model

[Dmitry87]

Im trying to add a 3D model of a car to a 3D QML scene. With only base texture it looks normal, but the windows are not transparent. To solve this problem I added an opacity map:

        PrincipledMaterial {
            id: material__62_material
            baseColor: "#ffffffff"
            baseColorMap: Texture {
                source: "maps/base.png"
                tilingModeHorizontal: Texture.Repeat
                tilingModeVertical: Texture.Repeat
            }
            opacityMap: Texture {
                source: "maps/opacity.png"
                tilingModeHorizontal: Texture.Repeat
                tilingModeVertical: Texture.Repeat
            }
        }

And now the model looks like B image

I tried to set different alpha value. Even if the opacity texture is completely white, I still can see through the model. The same way it looks if I add alpha channel to base.png
What configurations shall I use for correct alpha blending?

source code: https://drive.google.com/file/d/1Vnt3DafzEKMUUcbUkB4gQ9u8EhswbBjr/view?usp=sharing