Hi there! I don’t believe there is a property to change the shape of a button in Dundas.
You can actually add click events to any of the components you add to Dundas, so if I were creating an oval shape button and wanted to do it without javascript or adding css styles at all to reshape it, I would either use a png image I created myself and uploaded, or I would use the ellipse component and just add a click event to it - would that work for what you are trying to create?
To create some of the button like effects, if you look at events you can create some interactions on mouse enter / leave or mouse up down… if you want it to change color you can use multiple components. We’ve also used multiple objects behind each other on different layers and styled them differently and then changed layer on click to give some of the button interactions.