Gravit Designer discussion

[duplicated] How to make a compound path transparent [newbie question]

Hi there!

Can you please help me? The white parts of this image should be transparant (so not green, but ‘empty’, so that it 'll take the color of a background).

But I can’t select ‘Substract’ to make the selected compound path transparant.
Why can’t I select the ‘substract’ option? (or any of the other 3 options?)
Is there something I need to do that will make this option available?

Kind regards!

Please check this.