How to spin a 3D model in a view?

I can't get a 3D model to spin inside a swiftUI 2D view..

I had for example: Model3D(named: "Cupcake") .rotationEffect(Angle(degrees: rotationAngle))

But I'm unsure where to implement something like rotationAngle += 5

(I'm used to Unity and would put that in Update())