Sure MakerCase.com is cool but I ran into some issues when importing its DXF output into Fusion 360 for further work - the scaling was way off!
Instead I found this plugin: https://apps.autodesk.com/FUSION/en/Detail/Index?id=3012670521465945402&appLang=en&os=Win64 - It can do more or less the same thing as MakerCase and it will give you a box to work with in Fusion, where you can define your holes etc to cut out, and export to laser-cut DXF with Slicer. The only downside is that you can’t configure the fingers as well as you could on makercase.