Can't put a mask on mediaIn footage in fusion

Hi. new DaVinci resolve 15 user here.
I can' figure out how to mask footage with say an ellipse or rectangle like I do in fusion 9.
I want to mask out parts of my mediaIn clip(a png sequence), how is this possible?

/Nikolaj

I'll use a mattecontrol instead.
A mask option in MediaIn would be nice to have in the future.

I would suggest connecting the MediaIn into a merge as the foreground, and a transparent background node as the background. Then you can add a mask and it will apply it to the footage from the MediaIN.